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Revision as of 16:49, 15 March 2007 editPatrick (talk | contribs)Edit filter managers, Administrators68,523 edits →Dates containing a month and a day: date formatting.← Previous edit Latest revision as of 13:28, 26 December 2024 edit undoEEng (talk | contribs)Edit filter helpers, Autopatrolled, Extended confirmed users, New page reviewers, Pending changes reviewers, Template editors97,795 edits Undid revision 1265332048 by Waddie96 (talk) No, that's wrong 
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{{Short description|Misplaced Pages project page}}
{{style-guideline|]<br/>]<br/>],&nbsp;]}}
{{Redirect|WP:NUMBERS}}
{{MoS guideline|MOS:NUM|WP:MOSNUM}}
<noinclude>{{pp-move-indef}}</noinclude>
{{Style}} {{Style}}
<!--
This ''']''', like all ]s, attempts to encourage consistency and ease of reading. The guidelines here are just that: guidelines are not inflexible rules; one way is often as good as another, but if everyone does it the same way, ] will be easier to read, write and edit.
PLEASE MAKE MINOR CHANGES TO THIS TEXT ALSO TO THE EQUIVALENT TEXT AT MOS.
MORE SIGNIFICANT CHANGES, ESPECIALLY TO THE ACTUAL STYLE RECOMMENDATIONS, NEED TO BE FLAGGED AT THE WT:MOS TALK PAGE BEFORE IMPLEMENTATION HERE AND AT MOS, UNLESS THEY INVOLVE SECTIONS HERE THAT HAVE NO EQUIVALENT AT MOS (e.g. GEOGRAPHICAL COORDINATES).


FORMATTING: This page makes heavy and very particular use of a lot of specific formatting. To avoid confusion concerning the proper formatting of units, symbols, values, variables, code, etc., please observe the following markup conventions on this page:
New contributors are reminded that clear, informative and unbiased writing is always more important than presentation and formatting. (See ].)
- Use {{xt}} to mark up positive examples or required text.
- Use {{!xt}} to mark up negative examples or deprecated items.
- Use {{xtn}} to mark up items that may or may not be applied depending on context.
- Use {{xtg}} to mark up items that are very rarely applied{{snd}}dubious, deprecated, disputed, only used in one context (this template may not be needed on this page but is available).
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- Use '''bold''' to mark up inline headers.
- Use {{strong}} to mark up strong emphasis (rarely needed; {{em}} will usually suffice).
- Use <code>...</code> (or <code><nowiki>...</nowiki></code> if needed) to mark up code examples, including individual special characters. Do not use <tt>; this element no longer exists in HTML5.
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- Use {{tlx}} to illustrate or name templates (or use {{tl}} if nested inside <code>...</code>).
- Use <kbd>...</kbd> in running prose to indicate editor input choices for templates (not necessary in actual code examples inside <code>...</code>)
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- Use spaced en dashes, not run-together em dashes, especially with markup examples, so the dash cannot be confused as being part of the example.
- Use {{crossref}} for cross-references to other sections or pages. This produces consistent formatting, and helps identify cross-references in the code for periodic checking against "advice forking".
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- Avoid {{shy}} in or near examples; should probably only be used inside tables, when width is a concern.
- Do not mark up mention of units and the like outside the context of advice about their use. Example: 'Use {{xtn|m}} for "minute" only where there is no danger of confusion with meter'
.
-->


This page guides the presentation of numbers, dates, times, measurements, currencies, coordinates, and similar items in articles. The aim is to promote clarity, cohesion, and consistency, and to make the encyclopedia easier and more intuitive to use. For numbers, dates, and similar items in Misplaced Pages article titles, see the ] guideline.
==Dates==
===Years, decades, and centuries===
This section describes how to link to years, decades and centuries. See sections which follow, regarding when such linking is appropriate.


Where this manual gives options, maintain consistency within an article unless there is a good reason to do otherwise. The ] has ruled that editors should not change an article from one guideline-defined style to another without a substantial reason unrelated to mere choice of style; ] over optional styles is unacceptable.{{efn|1=See Arbitration Committee statements of principles in cases on style-related edit warring in ], ], and ]; and ].}} If discussion fails to resolve the question of which style to use in an article, defer to the style used by the first major contributor.
''See ] for a discussion on what is meant by AD and BC notation, and ] for a discussion on what is meant by CE and BCE notation.''
{{TOC limit|4}}


==General notes==
A page title that is just a positive whole number is always a year. Pages also exist for days of the year, decades, centuries and even millennia. The formats for references to years are:
* ]
** <nowiki>]</nowiki>
* ] (note no periods) ''or'' ]
** <nowiki>]</nowiki> ''or'' <nowiki>]</nowiki>
* ] ''or'' ] (Note: ''century'' is not capitalized, and "1700s" is not a century, but a decade)
** <nowiki>]</nowiki> ''or'' <nowiki>]</nowiki>
* ] ''or'' ] (or "tenth")
** <nowiki>]</nowiki> ''or'' <nowiki>]</nowiki>
* ] (''Not'' 1830's)
** <nowiki>]</nowiki>
* December ] (note that December is not linked)
** <nowiki>December ]</nowiki>
* ] ''or'' ]
** <nowiki>]</nowiki> ''or'' <nowiki>]</nowiki>


===Quotations, titles, etc.<span id="ExternException"></span>===
Articles for the year 500 BC and earlier should be redirected to the relevant ]. Articles for the year 1700 BC and earlier should be redirected to the relevant ]. Articles for the year 4000 BC and earlier should be redirected to the relevant ].


{{see also|Misplaced Pages:Manual of Style#Quotations}}
Note that the first century BC was from 100 BC to 1 BC (there was no ]) so 1700 BC would be the first year of the 17th century BC, 1800 BC would be the first year of the 18th century BC, etc. Similarly, 4000 BC was the first year of the fourth millennium BC, ''not'' the last year of the fifth millennium BC.


Quotations, titles of books and articles, and similar "imported" text should be faithfully reproduced, even if they use formats or units inconsistent with these guidelines or with other formats in the same article. If necessary, clarify via , article text, or footnotes.
When only an approximate date is available the abbreviation "''c.''" (Latin: ''circa'', "about") may be used; see the example at Rameses III below. When a date is uncertain—because the sources are unreliable—that fact should be noted and, if possible, the source specified. For example, "according to ], the ] was founded in 509 BC", or "The ] is traditionally said to have been composed in ]".


===Non-breaking spaces===
===Dates containing a month and a day===


Guidance on the use of ]s ("hard spaces") is given in some sections below, but not all situations in which hard spaces ({{t|nbsp}} or <code>&amp;nbsp;</code>) or {{tlx|nowrap}} may be appropriate are described. {{crossref|For further information see {{section link|Misplaced Pages:Manual of Style|Non-breaking spaces}} and ].}}
If a date includes both a month and a day, then the date should almost always be linked to allow ] to work, displaying the reader's chosen format. The day and the month should be linked together, and the year should be linked separately if present. For example:


==Chronological items==
*Month and day
**<code><nowiki>]</nowiki></code> → ]
**<code><nowiki>]</nowiki></code> → ]


===Statements likely to become outdated===
*Day, month, and year
**<code><nowiki>], ]</nowiki></code> → ], ]
**<code><nowiki>] ]</nowiki></code> → ] ]
**<code><nowiki>]</nowiki></code> → ]


{{Shortcut|MOS:SINCE|MOS:DATED|MOS:CURRENT|MOS:RECENT|MOS:NOW}}
To create a date that is linked but not converted, use a ] with alternate text, for example "<code><nowiki>]</nowiki></code>". This should only be done with good reason, such as in a ]. In this case, it may be preferable not to link the date at all, as the link does not then help with readers' date preferences.
{{See also|Misplaced Pages:Manual of Style/Words to watch#Relative time references|Misplaced Pages:Updating information|Misplaced Pages:As of}}


Except on pages that are inherently time-sensitive and updated regularly (e.g. ]), terms such as {{!xt|now}}, {{!xt|today}}, {{!xt|currently}}, {{!xt|present}}, {{!xt|to date}}, {{!xt|so far}}, {{!xt|soon}}, {{!xt|upcoming}}, {{!xt|ongoing}}, and {{!xt|recently}} should usually be avoided in favor of phrases such as {{xt|during the 2010s}}, {{xt|since 2010}}, and {{xt|in August 2020}}. Wording can usually be modified to remove the "now" perspective: not {{!xt|she is the current director}} but {{xt|she became director on 1 January {{CURRENTYEAR}}}}; not {{!xt|2010{{ndash}}present}} but {{xt|beginning in 2010}} or {{xt|since 2010}}. Terms likely to go out of date include {{!xt|best known for}}, {{!xt|holds the record for}}, etc.{{efn|See also ].}} For current and future events, use phrases such as {{xt|as of {{CURRENTMONTHNAME}} {{CURRENTYEAR}}}} or {{xt|since the beginning of {{CURRENTYEAR}}}} to signal the time-dependence of the information; use the template {{tl|as of}} (or {{tl|updated}}) in conjunction.
In article titles, dates will not be converted.
Relative-time expressions are acceptable for very long periods, such as geological epochs: {{xt|Humans diverged from other primates long ago, but ].}}


{{anchors|Dates|dates|Years|years|Months|Dates and years|Dates, months and years}}
There are some exceptions to the rule that dates with a month and a day should always be linked:
===Dates, months, and years===
{{Redirect|WP:YEAR|WikiProject Years|WP:YEARS}}
{{shortcut|MOS:DATE|MOS:DATEFORMAT|MOS:YEAR}}
* These requirements do not apply to dates in quotations or titles; {{crossref|see {{section link|Misplaced Pages:Manual of Style|Quotations}}}}.
* Special rules apply to citations; {{crossref|see {{section link|Misplaced Pages:Citing sources|Citation style}}}}.
* See also ].


====Formats<span id="Acceptable date formats"></span><span id="Date formats"></span>====
* Using the date formatting feature in section headers or links to them complicates ], see ].


{| class="wikitable"
* On disambiguation pages, ], not explanatory text.
|+ Acceptable date formats
|-
! style="width:40pt;"<!--undersized width specification means actual column width determined by widest word/unbreakable string in the column-->| General use
! style="width:40pt;"| {{nowrap|Only in limited situations<br>where brevity is helpful}}{{efn|name=brevity|1=For use in tables, infoboxes, references, etc. Only certain citation styles use abbreviated date formats. By default, Misplaced Pages does not abbreviate dates. ]}}
! Comments<!--no width specification means this column will pick up all remaining horizontal width-->
|-
| {{xt|2{{nbsp}}September 2001}}
| {{xt|2{{nbsp}}Sep 2001}}
| {{anchor|DMYCOMMA|DMY COMMA|dmy comma}} A comma doesn't follow the year unless otherwise required by context: {{unordered list| {{xt|The 5 May 1922 meeting was cancelled.}} | {{xt|Except Jones, who left London on 5 March 1847, every delegate attended the signing.}} }}
|-
| {{xt|September{{nbsp}}2, 2001}}
| {{xt|Sep{{nbsp}}2, 2001}}
| {{anchor|MDYCOMMA|MDY COMMA|mdy comma}} A comma follows the year unless ]: {{unordered list| {{xt|The weather on March 12, 2005, was clear and warm.}} | {{xt|Everyone remembers July{{nbsp}}20, 1969{{snd}}when humans first landed on the Moon. }} }}
|-
| {{xt|2{{nbsp}}September}}
| {{xt|2{{nbsp}}Sep}}
| rowspan=2 | Omit year only where there is no risk of ambiguity: {{ unordered list | {{xt|The 2012 London Olympics ran from 25{{nbsp}}July to 12{{nbsp}}September.}} | {{xt|January{{nbsp}}1 is New Year's Day.}} }}
|-
| {{xt|September{{nbsp}}2}}
| {{xt|Sep{{nbsp}}2}}
|-
| {{nobr|<small>''No equivalent for {{nobr|general use}}''</small>}}
| {{xt|2001-09-02}}
| Use {{nowrap|{{var|yyyy}}-{{var|mm}}-{{var|dd}}}} format only with ] dates from 1583 onward.{{efn|1=All-numeric {{nowrap|{{var|yyyy}}-{{var|mm}}-{{var|dd}}}} dates might be assumed to follow the ] standard, which mandates the Gregorian calendar. Also, technically all years must have (only) four digits, but Misplaced Pages is unlikely to need to format a date beyond the year 9999 anytime soon.<!--don't astronomers deal with dates in the 5 digits or beyond?-->}}
|-
| {{xt|September 2001}}
| {{xt|Sep 2001}}
|
|}


{{shortcut|MOS:UNLINKDATES}}{{anchor|Date autoformatting|Autoformatting and linking|Linking and autoformatting of dates|Things to avoid}}
* Within a quotation, the date should appear to all readers as it did in the source of the quotation.
* Dates, years, and other chronological items should be linked only when they are relevant to the subject ''and'' likely to be useful to a reader; this rule does not apply to articles that are explicitly on a chronological item, e.g. ], ] {{crossref|(as discussed at {{section link|Misplaced Pages:Linking|Chronological items}})}}.{{efn|1=The ] is deprecated. This change was made August 24, 2008, on the basis of ]. It was ratified in two December 2008 RfCs: ] and ].}}
* For issues related to dates in sortable tables, {{crossref|see {{section link|Help:Sortable tables|Configuring the sorting}}}} and {{crossref|{{section link|Help:Sortable tables|Date sorting problems}}}}, or consider using {{nowrap|{{tlx|dts|Nov 1, 2008}}.}}
* Phrases such as {{xt|]}} (or {{xt|July{{nbsp}}Fourth}}, but not {{!xt|July{{nbsp}}4th}}), {{xt|]}}, {{xt|]}}, and {{xt|]}} are proper names, to which rules for dates do not apply ({{xt|A typical Fourth of July celebration includes fireworks}}).


{{shortcut|MOS:DATESNO|MOS:BADDATE}}{{anchor|Unacceptable date formats}}
===Partial dates===
{| class="wikitable"
|+ Unacceptable date formats (except in ])
|-
! style="width:95pt;"| ] Unacceptable
! style="width:80pt;"| ] Corrected
! Comments
|-
|{{!xt|Sep'''.'''<!--←Bold to make dot more obvious.--> 2}}
|{{xt|Sep 2}}{{efn|name=brevity}}
|rowspan=2 | Do not add a full stop (period) to an abbreviated month or to the ].{{efn|1=For consensus discussion on abbreviated date formats like "Sep 2", see {{section link|Misplaced Pages talk:Manual of Style/Archive 151|RFC: Month abbreviations}}}}
|-
| {{!xt|9'''.'''<!--←Bold to make dot more obvious.--> June}}
| rowspan=5 | {{xt|9{{nbsp}}June}} or {{xt|June{{nbsp}}9}}
|-
| {{!xt|9 june}}<br>{{!xt|june 9}}
| Months should be capitalized.
|-
| {{!xt|9th June}}<br>{{!xt|June 9th}}<br>{{nowrap|{{!xt|the 9th of June}}}}
| Do not use ] ({{!xt|1st}}, {{!xt|2nd}}, {{!xt|3rd}}, etc.).
|-
|{{!xt|09-06}}<br>{{!xt|06-09}}
| Do not use these formats.
|-
| {{!xt|09 June}}<br>{{!xt|June 09}}
| Do not zero-pad day{{nbsp}}...
|-
| {{!xt|2007-4-15}}
| rowspan=6| {{xt|2007-04-15}}{{efn|name=brevity}}
| ... except in all-numeric {{nowrap|({{var|yyyy}}-{{var|mm}}-{{var|dd}}) format}}, in which month and day are zero-padded to two{{nbsp}}digits.
|-
| {{!xt|2007/04/15}}
| Do not use separators other than hyphens.
|-
| {{!xt|20070415}}
| Do not omit hyphens.
|-
| {{!xt|07-04-15}}
| Do not abbreviate year.
|-
| {{!xt|15-04-2007}}<br>{{!xt|04-15-2007}}<br>{{!xt|2007-15-04}}<!--The specific combination of values "04" and "15" (one below 12, the other above 12) used in these "Unacceptable" examples was chosen to allow there to be a single unambiguous entry in the "Acceptable" column.-->
| Do not use {{nowrap|{{var|dd}}-{{var|mm}}-{{var|yyyy}}}}, {{nowrap|{{var|mm}}-{{var|dd}}-{{var|yyyy}}}} or {{nowrap|{{var|yyyy}}-{{var|dd}}-{{var|mm}}}} formats.{{efn|1=These formats cannot, in general, be distinguished on sight, because there are usages in which ''{{nowrap|05-03-1991}}'' represents March{{nbsp}}5, and other usages in which it represents May{{nbsp}}3. According to ]:<!--lightly and silently edited-->
{{quote|Some years ago an American student I knew at university went into a panic when she received a note informing her that her exams were scheduled to start on 03-05-1991. She went into a severe weekend of cramming (studying for 18+ hours per day), until she was almost hospitalised from exhaustion. Only then did she realise that her exams didn't start on the 5th of March{{snd}}two weeks from the date she got the notice{{snd}}but the 3rd of May.<!-- The problem was a couple of her American friends initially presumed that the date mentioned was read as dd/mm/yy, but when the saw her reaction, then presumed she must be right and began studying like hell also. And her moment of doubt disappeared when she saw them studying like mad, presuming that if they are studying she must be correct in reading the date as mm/dd/yy. The end result was five extremely exhausted and highly embarrassed American students, who were never let forget their mistake by all other students, who teased them unmercifully afterwards.-->}}
In contrast, there is no common usage in which ''{{nowrap|1991-05-03}}'' represents anything other than May{{nbsp}}3.
}}
|-
| {{!xt|2007 April 15}}<br>{{!xt|2007 Apr 15}}
| Do not use these formats.<!--the comment doesn't say "Do not put year first" because in yyyy-mm-dd format the year DOES go first-->
|-
| {{!xt|7/2001}}<br>{{!xt|7-2001}}<br>{{!xt|07-2001}}<br>{{!xt|2001-07}}<br>{{!xt|2001 July}}<br>{{!xt|July of 2001}}
| rowspan=2| {{xt|July 2001}}
| Do not use these{{nbsp}}formats.
|-
| {{!xt|July''',''' 2001}}
| rowspan=2| No comma between month and{{nbsp}}year.
|-
| {{!xt|3 July''',''' 2001}}
| {{xt|3{{nbsp}}July 2001}}
|-
| {{!xt|July 3 2001}}
| {{xt|July{{nbsp}}3''',''' 2001}}
| Comma required between day and{{nbsp}}year.
|-
| {{!xt|the{{nbsp}}'''{{'}}'''97 elections}}<br>{{!xt|the{{nbsp}}97 elections}}
| {{xt|{{nowrap|the 1997 elections}}}}
| Do not abbreviate year.
|-
| {{!xt|Copyright MMII}}
| {{xt|Copyright 2002}}
| ] are not normally used for{{nbsp}}dates.
|-
| {{!xt|{{nowrap|Two thousand one}}}}
| {{xt|2001}}
| rowspan=2| Years and days of the month are not normally written in{{nbsp}}words.
|-
| {{!xt|the first of May}}<br>{{!xt|May the first}}
| {{nowrap|{{xt|1{{nbsp}}May}} or {{xt|May{{nbsp}}1}}}}
|-
| {{!xt|June 0622}}
| {{xt|June 622}}
| Do not zero-pad years.
|-
| {{!xt|June 2''','''015}}
| {{xt|June 2015}}
| Do not add a comma to a four-digit year.
|-
| {{!xt|{{nowrap|sold in the year 1995}}}}
| {{xt|sold in 1995}}
| Write "the year" only where needed for clarity ({{xt|{{nowrap|About 200 ships}} arrived in {{nowrap|the year 300}}}}).
|}


=====Consistency=====
If the date does not contain both a month and a day, date preferences do not apply: linking or not linking the date will make no difference to the text that the reader sees. So when considering whether such a date should be linked or not, editors should take into account the usual considerations about links, including the recommendations of ].


{{anchor|Format consistency}}
There is consensus among editors that bare month and day names should not be linked unless there is a specific reason that the link will help the reader to understand the article. There is less agreement about links to years. Some editors believe that links to years are generally useful to establish context for the article. Others believe that links to years are rarely useful to the reader and reduce the readability of the text. Another possibility is to link to a more specific article about that year, for example <nowiki>]</nowiki>, although some people find this unintuitive because the link leads to an unexpected destination. <!-- The last sentence is also at ], so if it's changed here it should be changed there too -->
{{shortcut|MOS:DATEUNIFY}}
{{unordered list
| '''Dates in article body text'''{{efn|name=body|''Body'' in this context means the main prose of the article, as distinguished from reference citations, tabular data, infoboxes, navigation templates, and metadata such as hatnote templates, etc. Other parts of the Manual of Style may use ''body'' to mean 'the bulk of the article after the lead section', but that is not the meaning here. Misplaced Pages's article leads are not written in a different prose style from the material following them.}} should all use the same format: {{xt|She fell ill on {{nobr|25 June 2005}} and died on {{nobr|28 June}}}}, not {{!xt|She fell ill on {{nobr|25 June 2005}} and died on {{nobr|June 28}}}}.
| '''Publication dates''' in an article's citations should all use the same format, which may be:{{unordered list
| the format used in the article body text,
| an abbreviated format from the ], provided the day and month elements are in the same order as in dates in the article body
| the format expected in the ] being used (but all-numeric date formats other than {{nowrap|{{var|yyyy}}-{{var|mm}}-{{var|dd}}}} must still be avoided).}}
For example, publication dates within a single article might be in one, but only one, of these formats (among others):{{unbulleted list|style=margin-left: 1.5em
| {{xt|Jones, J. (20 September 2008)}}
| {{xt|Jones, J. (September 20, 2008)}}}}
If an article uses a template such as {{tlx|Use mdy dates}} or {{tlx|Use dmy dates}}, then ] and ] templates automatically render dates ({{para|date}}, {{para|access-date}}, {{para|archive-date}}, etc) in the specified format, regardless of the format they are entered in. (The {{para|cs1-dates}} parameter can be used to fine-tune the generated output, {{crossref|pw=y|see {{section link|Template:Use mdy dates|Auto-formatting citation template dates}}}}.)
| '''Access and archive dates''' in an article's citations should all use the same format, which may be:{{unordered list
| the format used for publication dates in the article (see above);
| the format expected in the citation style adopted in the article; or
| {{nowrap|{{var|yyyy}}-{{var|mm}}-{{var|dd}}}}}}
For example, access/archive dates within a single article might be in one, but only one, of these formats (among others):{{unbulleted list|style=margin-left: 1.5em
| {{xt|Jones, J. (September 20, 2008){{nbsp}}... Retrieved February 5, 2009.}}
| {{xt|Jones, J. (20 Sep 2008){{nbsp}}... Retrieved 5 Feb 2009.}}
| {{xt|Jones, J. (20 September 2008){{nbsp}}... Retrieved 2009-02-05.}}}}
When a citation style does not expect differing date formats, it is permissible to normalize publication dates to the article body text date format, and/or access/archive dates to either, with date consistency being preferred.}}


=====Strong national ties to a topic=====
Examples of links which do not respond to readers' date preferences:
*Year only: <nowiki>]</nowiki> → ].
*Month only: <nowiki>]</nowiki> → ]. Generally should not be linked.
*Century: <nowiki>]</nowiki> → ].
*Decade: <nowiki>]</nowiki> → ].
*Year and month: <nowiki>] ]</nowiki> → ] ].
*Recent year and month: <nowiki>]</nowiki> → ]. Currently articles only exist for combinations from the year 1999 to the present.
*Day of the week (with or without other date elements): <nowiki>]</nowiki> → ]. Generally should not be linked.


{{shortcut|MOS:DATETIES}}
===Yearless dates===
Articles addressing recent events often omit the year, under the impression that "]" clearly refers to the recent past. However, as time goes on, the context will be lost; therefore the first use of a date should include the year. Once the year is clearly established, yearless dates can be used judiciously in nearby prose. See also ] and ].


For any given article, the choice of date format and the choice of national variety of English (see {{section link|Misplaced Pages:Manual of Style#Strong national ties to a topic}}) are independent issues.
===Date formats related to topics===
* Articles on topics with strong ties to a particular English-speaking country should generally use the date format most commonly used in that nation. For the United States this is (for example) {{nobr|{{xt|July 4, 1976}}}}; for most other English-speaking countries it is {{nobr|{{xt|4 July 1976}}}}.
If the topic itself concerns a specific country, editors may choose to use the ] used in that country. This is useful even if the dates are linked, because new users and users without a Misplaced Pages account do not have any date preferences set, and so they see whatever format was typed. See ] for more guidance.
* Articles related to Canada may use either format with (as always) consistency within each article. {{see below|Retaining existing format}}
*{{shortcut|MOS:MILFORMAT}} In topics where a date format that differs from the usual national one is in customary usage, that format should be used for related articles: for example, articles on the modern US military, including biographical articles related to the modern US military, should use day-before-month, in accordance with US military usage.


=====Retaining existing format<span id="Retaining the existing format"></span>=====
===ISO date formats===


{{shortcut|MOS:DATERET|MOS:DATEVAR}}
] dates, for example 1958-02-17, are unambiguous. However, they are not common in English prose, and are therefore unfamiliar to many readers. Accordingly, they should generally not be used in normal prose. This applies even if they are in a link: although the software will convert such dates according to users' date preferences (for example, <nowiki>]</nowiki> → ]), new users and unregistered users do not have any date preferences set, and will therefore see the unconverted ISO 8601 date.
{{See also|Misplaced Pages:Manual of Style#Retaining existing styles}}
* If an article has evolved using predominantly one date format, this format should be used throughout the article, unless there are reasons for changing it based on the topic's strong ties to a particular English-speaking country, or consensus on the article's talk page.
* The date format chosen in the first major contribution in the early stages of an article (i.e., the first non-stub version) should continue to be used, unless there is reason to change it based on the topic's strong ties to a particular English-speaking country, or consensus on the article's talk page.
* Where an article has shown no clear sign of which format is used, the first person to insert a date is equivalent to "the first major contributor".


====Era style<span id="Year numbering systems"></span><span id="Eras and other very long periods"></span>====
This advice only applies to dates in normal prose. ISO 8601 dates may sometimes be useful elsewhere; for example, they are useful in lists, tables, for dates of birth/death, for conciseness and ease of comparison.


{{Redirect|WP:BCE|the copyediting guide|Misplaced Pages:Basic copyediting}}
===Incorrect date formats===
{{shortcut|MOS:ERA|MOS:BCE}}
* Do not use numbers to express a month, except in ISO 8601 format. Always express a month as a whole word (e.g. "February" ''not'' "2"). Do not use abbreviations like "Feb" unless the available space is extremely limited, such as in a table, infobox, or the like.
* The default ]s are ] ({{xt|BC}} and {{xt|AD}}) and ] ({{xt|BCE}} and {{xt|CE}}). Either convention may be appropriate for use in Misplaced Pages articles depending on the article context. Apply {{section link|Misplaced Pages:Manual of Style|Retaining existing styles}} with regard to changes from one era to the other.
* Do not use two digits to express a year unless at the end of a range, e.g., "1970–87" (the same for BC). In all other cases, use four digits for years and decades after AD 999 (the same for BC). Using the less formal two-digit form for a decade is acceptable when not ambiguous; for example, when referring to the decade of the 20th century known as "the eighties", use "1980s" or, less often, "the '80s", not just "80s".
** Use either the BC{{ndash}}AD or the BCE{{ndash}}CE notation consistently within the same article. Exception: do not change ], titles, etc.
** An article's established era style should not be changed without reasons specific to its content; seek consensus on the talk page first (applying {{section link|Misplaced Pages:Manual of Style|Retaining existing styles}}) by opening a discussion under a heading using the word ''era'', or another similarly expressive heading, and briefly stating why the style should be changed.
** BCE and CE or BC and AD are written in upper case, unspaced, without a full stop (period), and separated from the numeric year by a space ({{xt|5{{nbsp}}BC}}, not {{!xt|5BC}}). It is advisable to use a ].
** AD appears before or after a year ({{xt|AD{{nbsp}}106}}, {{xt|106{{nbsp}}AD}}); BCE, CE, and BC always appear {{em|after}} ({{xt|106{{nbsp}}CE}}, {{xt|3700{{nbsp}}BCE}}, {{xt|3700{{nbsp}}BC}}).
** In general, omit CE or AD, except to avoid ambiguity or awkwardness.
*** Typically, write {{xt|The ] took place in 1066}} not {{!xt|1066{{nbsp}}CE}} or {{!xt|AD{{nbsp}}1066}}.
*** But {{xt|] lived at the end of the 3rd century AD}} (not simply {{!xt|at the end of the 3rd century}}) may avoid confusion unless the era is clear from context.
*** One- and two-digit years may look more natural with an era marker ({{nobr|{{xt|born in 2 AD}}}} or {{nobr|{{xt|born January 15, 22 CE}}}}, not {{nobr|{{!xt|born in 2}}}} nor {{nobr|{{!xt|January 15, 22}}).}}
*** Ranges beginning in BC{{\}}BCE should specify the ending era: write {{nobr|{{xt|450 to 200 BCE}}}} or {{nobr|{{xt|450 BC to 200 BC}}}} or {{nobr|{{xt|450 BCE to 200 CE}}}}, but not {{nobr|{{!xt|450 BCE to 200}}}}. {{see below|]}}
* '''Uncalibrated (BCE) radiocarbon dates:''' ] dates can diverge widely, and some sources distinguish the two only via BCE or BC (for calibrated dates) versus bce or bc (uncalibrated). When feasible, avoid uncalibrated dates except in direct quotations, and even then ideally give the calibrated date in a footnote or square-bracketed note{{snd}}{{xt|}}, or at least indicate the date type{{snd}}{{xt|}}. This also applies to other dating systems in which a calibration distinction is drawn.
* '''BP or YBP''': In scientific and academic contexts, BP (Before Present) or YBP (years Before Present) are often used. (''Present'' in this context by convention refers to January{{nbsp}}1, 1950.) Write {{xt|3000 years{{nbsp}}BP}} or {{xt|3000{{nbsp}}YBP}} or {{xt|3000{{nbsp}}years before present}} but not forms such as {{!xt|3000 before present}} and {{!xt|3000 years before the present}}. If one of the abbreviated forms is used, link to '']'' on first use: {{xt|The Jones artifact was dated to 4000{{nbsp}}], the Smith artifact to 5000 YBP.}}
* {{anchor|Other_era_systems}}'''Other era systems''' may be appropriate in an article. In such cases, dates should be followed by a conversion to Anno Domini or Common Era, and the first instance linked: {{xt|Qasr-al-Khalifa was built in {{nobr|221 ] (836 CE)}}}}, or {{nobr|{{xt|in 836 AD (221 ])}}}}.
** ] is similar to the Common Era. There is no need to follow a year expressed with astronomical year numbering with a conversion to Common Era. The first instance of a non-positive year should still be linked: {{xt|The March equinox passed into Pisces in ].}} (The expressions {{xt|&minus;67}} and {{xt|68{{nbsp}}BCE}} refer to the same year.)<!--I suppose we should say something somewhere about use of &minus in this case-->


====Julian and Gregorian calendars====
* Use consistent date formatting throughout an article, unless there is a good reason to vary it.


{{shortcut|MOS:OSNS|MOS:JG}}
* Do not use ordinal suffixes:
{{see also|Old Style and New Style dates}}
** Incorrect: "February 14th" and "14th February"
** Correct: "February 14" and "14 February"


A date can be given in any appropriate calendar, as long as it is (at the minimum) given in the ] or the ] or both, as described below. For example, an article on the early ] may give dates in both ] and Julian calendars. Where a calendar other than the Julian or Gregorian is used, the article must make this clear.
* Do not use articles:
* Current events are dated using the Gregorian calendar.
** Incorrect: "the 14th of February"
* Dates of events in countries using the Gregorian calendar at that time are given in the Gregorian calendar. This includes some of the ], the ] from 14{{nbsp}}September 1752, and Russia from 14{{nbsp}}February 1918 {{crossref|(see ])}}.
** Correct: "February 14" and "14 February"
* Dates before 15{{nbsp}}October 1582 (when the Gregorian calendar was first adopted in some places) are normally given in the Julian calendar.
* Dates after 4{{nbsp}}October{{nbsp}}1582 in a place where the Julian calendar was observed should be given in the Julian calendar.
* For either the Julian or Gregorian calendars, the beginning of the year should be treated as 1{{nbsp}}January even if a different start-of-year date was observed in the place being discussed.
* Dates for Roman history before 45{{nbsp}}BC are given in the ], which was neither Julian nor Gregorian. When (rarely) the Julian equivalent is certain, it may be included.
* For dates in early Egyptian and Mesopotamian history, Julian or Gregorian equivalents are often uncertain. Follow the consensus of reliable sources, or indicate their divergence.


The dating method used should follow that used by reliable secondary sources (or if reliable sources disagree, that used most commonly, with an explanatory ]). The guidance above is in line with the usage of reliable sources such as '']'',<ref>{{cite encyclopedia | encyclopedia = American National Biography |title = Editorial note | date = 1999 | publisher = Oxford University Press | editor1-last = Garraty | editor1-first = John A. | editor2-last = Carnes | editor2-first = Mark C. | pages = xxi&ndash;xxii}}</ref> '']'', and '']''.{{efn|1=The calendar practices of ''Oxford Dictionary of National Biography'' and ''Encyclopædia Britannica'' can be inferred by looking up the birth and death dates of famous, well-documented individuals.}}
* Do not put a comma or the word "of" between a month and year:
** Incorrect: "December, 1945" and "December of 1945"
** Correct: "December 1945"


Where it is not obvious that a given date should be given in Julian alone or in Gregorian alone, consider giving both styles, for example by using {{tl|OldStyleDate}}. If a date appears without being specified as Old Style or New Style, tagging that date with {{tl|which calendar?}} will add the page to ] for further attention.
* Do not use an apostrophe to indicate a decade:
** Incorrect: 1970's
** Correct: 1970s


If an article contains Julian calendar dates after 4 October 1582 (as in the ]), or if a start-of-year date other than 1 January was in force in the place being discussed, or both, a footnote should be provided on the first usage, explaining the calendar usage adopted for the article. The calendar usage should be compatible with this guideline.
===Direct quotations===
An important exception to these guidelines is that direct quotations—the word-for-word reproduction of a written or oral text—should ''not'' be altered to conform to the Misplaced Pages "Manual of Style". In other words, a paragraph such as this (fictional) quotation from a newspaper report is fine as is:
: "Tony Blair, responding to critics in his party, said 'The world has totally changed since the 11th of September.' He was echoing earlier sentiments by Lord Ronald McDonald, who said that 'nine-eleven' was the day that the American public woke up to the reality of terrorism."


====Ranges<span id="Date ranges"></span>====
===Dates of birth and death===
{{anchors|Other date ranges|Dates of birth and death}}
* '''Charles Darwin''' (] ]&ndash;] ])
{{shortcut|MOS:DATERANGE|MOS:DOB|MOS:YEARRANGE}}
**Locations should be included in the biography portion of the body article. For example, "(] ] in Shrewsbury, Shropshire, England–] ] in Downe, Kent, England)" should be separated to "(] ]–] ]) … He was born in Shrewsbury, Shropshire, England … He died in Downe, Kent, England".
{{See also|Misplaced Pages:Manual of Style#Number ranges}}
* '''Socrates''' (]–]) (or "BCE")
{{Redirect|MOS:DIED|euphemisms for "died"|Misplaced Pages:Manual of Style/Words to watch#Euphemisms}}
** When only the years are known.
* A simple '''year{{ndash}}year''' range is written using an ] (<code>–</code>, <code>&amp;ndash;</code> or {{tlx|ndash}}, or {{tlx|nbnd}} for a non-breaking en dash), not an em dash, hyphen, or slash; this dash is {{em|unspaced}} (that is, with no space on either side); and the end year is usually given in full:
* '''Serena Williams''' (born ] ])
** {{xt|1881{{ndash}}1882}};{{nbsp}} {{xt|1881{{ndash}}1886}} (not {{!xt|1881{{ndash}}86}});{{nbsp}} {{xt|1881{{ndash}}1892}} (not {{!xt|1881{{ndash}}92}})
** For a person still living at the time the article was written.
*** ''Markup:'' <code>1881{{tl|ndash}}1882</code> or <code>1881&amp;ndash;1882</code>
**Notice that the form is ''not'' "(] ]–)"
** Although non-abbreviated years are generally {{em|preferred}}, '''two-digit ending years''' ({{xt|1881{{ndash}}82}}, but never {{!xt|1881{{ndash}}882}} or {{!xt|1881{{ndash}}2}}) {{em|may}} be used in any of the following cases: (1) two consecutive years; (2) ] and tables where space is limited (using a single format consistently in any given table column); and (3) in certain topic areas if there is a very good reason, such as matching the established convention of reliable sources.{{efn|A change from a preference for two digits, to a preference for four digits, on the right side of ''year{{ndash}}year'' ranges was implemented in July 2016 per ].<!--The change can be seen at https://en.wikipedia.org/?diff=744053720&oldid=744052603-->}} For consistency, avoid abbreviated year ranges when they would be used alongside non-abbreviated ranges within an article (or related pages, if in titles). Never use abbreviated years for ranges across centuries ({{xt|1999{{ndash}}2000}}, not {{!xt|1999{{ndash}}00}}) or for years from the first millennium ({{xt|886{{ndash}}887}}, not {{!xt|886{{ndash}}87}}).
* '''Offa''' (died ] ])
** The '''{{visible anchor|slash notation}}''' ({{xt|2005/2006}}) may be used to signify a fiscal year or other special period, if that convention is used in reliable sources.
** When the date of birth is unknown.
* Other "simple" ranges use an {{em|unspaced}} en dash as well:
* '''Genghis Khan''' (c.]–], ])
** '''day{{ndash}}day''': {{xt|5{{ndash}}7{{nbsp}}January 1979}};{{nbsp}} {{xt|January{{nbsp}}5{{ndash}}7, 1979}};{{nbsp}} {{xt|elections were held March 5{{ndash}}8}}.
** When the date of birth is known approximately.
** '''month{{ndash}}month''': {{xt|the 1940 peak period was May{{ndash}}July}};{{nbsp}} {{xt|the peak period was May{{ndash}}July{{nbsp}}1940}};{{nbsp}} (but {{xt|the peak period was {{nobr|May 1940{{snd}}July}} 1940}} uses a {{em|spaced}} en dash; {{crossref|see below}})
* '''Dionysius Exiguus''' (c.]–c.])
* In certain cases where at least one item on either side of the en dash contains a space, then a {{em|spaced}} en dash ({{tlx|snd}}) is used. For example:
** When dates of birth and death are known approximately.
** '''between specific dates in different months''': {{xt|They travelled {{nobr|June 3{{snd}}August{{nbsp}}18,}} 1952}};{{nbsp}} {{xt|They travelled 3 June{{snd}}18{{nbsp}}August 1952}}
*'''Robert Menli Lyon''' (born ], date of death unknown)
** '''between dates in different years''':
**When the date of death is unknown, but the person is certainly now dead.
*** {{xt|'''Charles Robert Darwin''' (12{{nbsp}}February {{nobr|1809{{snd}}19 April}} 1882) was an English naturalist{{nbsp}}...}}
* '''Rameses III''' (reigned c.]E–c.]E)
**** ''Markup:'' <code>12{{t|nbsp}}February 1809{{tl|snd}}19{{t|nbsp}}April 1882</code> or {{nowrap|<code>12&amp;nbsp;February 1809&amp;nbsp;&amp;ndash; 19&amp;nbsp;April 1882</code>}}
** When only the dates of the reign are known and only approximately.
*** {{xt|'''Abraham Lincoln''' (February{{nbsp}}12, 1809{{snd}}April{{nbsp}}15, 1865) was the 16th president of{{nbsp}}...}}
* '''Osmund''' (] 760–772)
** '''between months in different years''': {{xt|The exception was in force August {{nobr|1892{{snd}}January}} 1903}};{{nbsp}} {{xt|The Ghent Incursion (March 1822{{snd}}January{{nbsp}}1, 1823) was ended by the New Year's Treaty}}
** When the person was known to have been alive (flourishing) at certain dates. Note that <nowiki> ] </nowiki> is used to link to ], in case the meaning is not familiar.
*** ''Markup:'' <code>March 1822{{t|snd}}January{{t|nbsp}}1, 1823</code> or {{nowrap|<code>March 1822&amp;nbsp;&amp;ndash; January&amp;nbsp;1, 1823</code>}}
*'''Aethelwalh''' (] c.660–685)
** Where '''era designations''', '''c.<!-- guideline below advocates against use of the unabbreviated "circa" or use of italics for "c." -->''' or '''other modifiers''' are present {{See below|{{section link||Uncertain, incomplete, or approximate dates}}}}:
** Here the person was known to have been alive approximately as early as 660, and to have died in 685.
*** if the modifier '''applies to only one of the two endpoints of the range''', use a {{em|spaced}} en dash: {{nobr|{{xt|150 BCE{{snd}}50 BCE}}}}, {{nobr|{{xt|5 BC{{snd}}12 AD}}}}, {{nobr|{{xt|c. 1393{{snd}}1414}}}}
*** if the modifier '''applies to the range as a whole''', {{em|disregard}} the modifier: {{nobr|{{xt|150{{ndash}}50 BCE}}}}, {{nobr|{{xt|reigned 150 BCE{{snd}}50 BCE}}}}, {{nobr|{{xt|reigned 150{{ndash}}50 BCE}}}}, {{nobr|{{xt|{{reign|{{circa|1393|lk=no}}|1414}}}}}}, {{nobr|{{xt|{{reign|1393|1414|lk=no}}}}}}.
* Use an en dash, or a word such as ''from'' or ''between'', but not both: {{xt|from 1881 to 1886}} (not {{!xt|{{nobr|from 1881{{ndash}}1886}}}});{{nbsp}} {{xt|between June{{nbsp}}1 and July{{nbsp}}3}} (not {{!xt|{{nobr|between June{{nbsp}}1{{snd}}July{{nbsp}}3}}}})
{{shortcut|MOS:DATETOPRES|MOS:TOPRESENT}}{{anchors|Date range to present}}
* ] says "terms such as ... 'present' should usually be avoided". For ranges, if '''"to present"''' or '''"{{ndash}}present"''' is used, the current year (or, in cases where necessary, date) of "present" at the time of writing should be included. Thus {{nobr|{{xt|1982{{ndash}}present (as of {{CURRENTYEAR}})}}}}{{snd}}if writing in {{CURRENTYEAR}}{{snd}}is preferable to {{nobr|{{xt|1982{{ndash}}present}}}}. If the "from" date has an internal space, a spaced en dash is used. Other constructions may be more appropriate in prose {{crossref|(see {{section link||Statements likely to become outdated}})}}. An alternative form is {{xt|Since 1982}}.


:In tables and infoboxes where space is limited, ''pres.'' may be used ({{xt|1982{{ndash}}pres.}}). Do not use incomplete-looking constructions such as {{nobr|{{!xt|1982{{ndash}}}}}} and {{nobr|{{!xt|1982{{ndash}}... }} .}}
Note the preferred use of "c." rather than "circa", "ca." or a question mark.
:*Consider adding the {{t|As of}}, or {{t|Update after}} templates to such constructions, depending on how important it is for editors to keep "present" up to date.


* <p>For a '''person still living''': {{xt|'''Serena Williams''' (born September{{nbsp}}26, 1981) is a{{nbsp}}...}}, not {{!xt|(September{{nbsp}}26, 1981{{snd}})}} or {{!xt|(born on September{{nbsp}}26, 1981)}}.</p><p>Do not use <code>*</code> to indicate ''born''; use <code>b.</code> only where space is limited, e.g., in tables and infoboxes; use either <code>born</code> or <code>b.</code> consistently in any given table column.</p>
Ranges of dates are given with a spaced or unspaced hyphen or en dash (&amp;ndash;). See ].
* <p>Where '''birthdate is unknown''': {{xt|'''John Smith''' (died May{{nbsp}}1, 1622)}} or {{xt|'''John Smith''' (died 1622)}}</p><p>Do not use <code>†</code> to indicate ''died''; use <code>d.</code> only where space is limited, with consistency within any given table column.</p>
* <p>An '''overnight period''' may be expressed using a slash between two contiguous dates: {{xt|the night raids of 30/31{{nbsp}}May 1942}} or {{xt|raids of 31{{nbsp}}May{{nbsp}}/ 1{{nbsp}}June 1942}}.</p><p>Or use an en dash: (unspaced) {{xt|raids of 30{{ndash}}31{{nbsp}}May 1942}};{{nbsp}} (spaced) {{xt|raids of {{nobr|31{{nbsp}}May{{snd}}1{{nbsp}}June}} 1942}}.</p>
* The {{tlx|Age}} template can keep ages current in infoboxes and so on:
** <code><nowiki>{{age|1989|7|23}}</nowiki></code> returns: {{xt|{{age|1989|7|23}}}}
** <code><nowiki>{{age|1989|7|23}}-year-old</nowiki></code> returns: {{xt|{{age|1989|7|23}}-year-old}}
** <code><nowiki>{{age|1989|7|23}} years old</nowiki></code> returns: {{xt|{{age|1989|7|23}} years old}}
* ] are available for other age calculations.


====Uncertain, incomplete, or approximate dates====
===Seasons===
Because the seasons are reversed in each hemisphere—while areas near the ] tend to have just ] and ]s—neutral wording should be used to describe times of the year, such as "in early 1990", "in the second quarter of 2003", "around September" or an exact date, rather than references to seasons, unless there is some particular need to do so (e.g., "the autumn harvest"). It is ambiguous to say that ] landed on the Moon in the summer of 1969—whose summer? However, quoted references to seasons should not be changed.


<!--This section/anchor linked to from MOS:DATERANGE.-->
===Eras===
{{shortcut|MOS:APPROXDATE|MOS:CIRCA}}
*Both the BCE/CE era names and the BC/AD era names are acceptable, but should be consistent within an article.
* To indicate "around", "approximately", or "about", the use of the {{tlx|circa}} template is preferred at first occurrence over just {{!xt|c.}} At later occurrences, {{xt|c.}} is preferred over {{!xt|circa}}, {{!xt|c}}, {{!xt|ca}}, {{!xt|ca.}}, {{!xt|around}}, {{!xt|approximately}}, or {{!xt|approx.}}:
** {{xt|'''John Sayer''' ({{circa|1750}}{{snd}}2{{nbsp}}October 1818){{nbsp}}...}}
** {{xt|the Igehalkid dynasty of Elam, {{circa|1400{{nbsp}}BC}}{{nbsp}}...}}
* Where both endpoints of a range are approximate, <code>c.</code> should appear before each date (the two-argument form of {{tlx|circa}} does this):
** {{xt|'''Dionysius Exiguus''' ({{circa|470|540}}){{nbsp}}...}} (not {{!xt|'''Dionysius Exiguus''' ({{circa}} 470{{snd}}540){{nbsp}}...}})
** {{xt|'''Rameses III''' (reigned {{circa|1180|1150{{nbsp}}BCE}}){{nbsp}}...}} (not {{!xt|'''Rameses III''' (reigned {{circa}} 1180{{snd}}1150{{nbsp}}BCE){{nbsp}}...}})
* Where birth/death limits have been inferred from known dates of activity:
** {{xt|'''Offa of Mercia''' (before 734{{snd}}26{{nbsp}}July 796){{nbsp}}...}}
** {{xt|'''Robert Menli Lyon''' (1789{{snd}}after 1863){{nbsp}}...}}
** {{xt|'''Ambrose Gwinnett Bierce''' (June 24, 1842{{snd}}after December 26, 1913){{nbsp}}...}}<!--Relationship between "before/after" and "fl." needs to be clarified.-->
* When birth and death dates are unknown, but the person is known to have been active ("flourishing") during certain years, {{xt|fl.}}, <code><nowiki>]</nowiki></code>, or {{tlx|fl.}} may be used:
** {{xt|'''Jacobus Flori''' (]{{nbsp}}1571{{ndash}}1588) ...}}
** {{xt|'''Jacobus Flori ''fils''''' ({{floruit|{{circa|1600}}{{snd}}1616|lk=off}}) ...}}<!-- example used to illustrate that not all uses of "fl." will require an unspaced en dash -->
: The corresponding template {{tlx|r.}} produces reign output: {{xt|{{r.|540|562}}}}, though it is often clearer to write out {{xt|reigned 540–562}}, especially in the lead. With both of these templates, linked forms should not be used on disambiguation pages, and "active" followed by the range is a better alternative for occupations not relating to the composition of works, whether it be musical, grammatical, historical, or any other such work.
* When a date is known to be either of two years (e.g. from a ] or ] year conversion, or a known age at death):
** {{xt|'''Anne Smith''' (born 1912 or 1913; died 2013){{nbsp}}...}}
* Other forms of uncertainty should be expressed in words, either in article text or in a footnote: {{xt|April{{nbsp}}14, 1224 (unattested date)}}. Do not use a question mark ({{!xt|1291?}}), because it fails to communicate the nature of the uncertainty.
* Where {{xt|c.}} or a similar form appears ''which applies only to one of the two endpoints of the range'', use a spaced en dash (<code><nowiki>{{snd}}</nowiki></code>).
** ''Examples'': {{xt|{{nobr|1896{{snd}}after 1954}}}}, {{xt|{{nobr|470{{snd}}{{c.|540}}}}}}, {{xt|{{nobr|{{c.|470}}{{snd}}540}}}}, {{xt|{{nobr|{{c.|470|540}}}}}}.
** ''Markup'': {{nobr|<code><nowiki>1896{{snd}}after 1954</nowiki></code>}}, {{nobr|<code><nowiki>470{{snd}}{{c.|540}}</nowiki></code>}}, {{nobr|<code><nowiki>{{c.|470}}{{snd}}540</nowiki></code>}}, {{nobr|<code><nowiki>{{c.|470|540}}</nowiki></code>}}.<!-- n.b.: the {{c}} template is unrelated, as it deals with linking to categories -->
* Where a modifier ''applies to the range as a whole'', such as {{xt|fl.}} and {{xt|{{abbr|r.|reigned}}}}, use a spaced or unspaced en dash as appropriate to the range if this modifier is disregarded.
** ''Examples'': {{xt|]{{nbsp}}1571{{ndash}}1588}}, {{xt|{{floruit|{{circa|1600}}{{snd}}1616|lk=off}}}}, {{xt|{{reign|{{circa|1353}}|1336}}{{nbsp}}BC}}, {{xt|{{reign|1989|2019|lk=no}}{{nbsp}}CE}}, {{xt|{{reign|2019{{nbsp}}CE|present|lk=no}}}}.
* Some modifiers, such as {{xt|traditionally}}, {{xt|around}}, {{xt|BH}}, and {{xt|CE}}, sometimes apply to only one endpoint, and sometimes to the whole range. Whether the en dash should be spaced or unspaced should still be determined by the above guidelines, but consider rephrasing if the result is ambiguous or possibly confusing.
** {{nobr|{{xt|traditionally 1571{{ndash}}1588}}}} and {{nobr|{{xt|traditionally 1571{{snd}}1588}}}} mean two different things, which may not be obvious to the reader.
** {{nobr|{{xt|traditionally 1585{{snd}}{{circa|1590}}}}}} can have two different meanings, and which one is meant may not be clear.
** {{nobr|{{!xt|400 BCE{{snd}}200}}}} clearly has {{xt|BCE}} applying only to one endpoint, but the range is ambiguous. Consider using {{nobr|{{xt|400{{ndash}}200 BCE}}}}, {{nobr|{{xt|400 BCE{{snd}}200 BCE}}}}, or {{nobr|{{xt|400 BCE{{snd}}200 CE}}}}, depending on what is meant.
** Technically, {{nobr|{{!xt|] 13{{snd}}57}}}} is currently<!-- it may not be in the future --> unambiguous (because there is no Taishō 57), but it is better to use both era designations in this case: {{nobr|{{xt|] 13{{snd}}] 57}}}}.
* Ideally a non-breaking space should follow very short modifiers such as {{xt|c.}}, {{xt|fl.}}, {{xt|r.}}, {{xt|{{abbr|b.|born}}}}, and {{xt|{{abbr|d.|died}}}}


===Times of day<span id="Time of day"></span>===
*Normally you should use plain numbers for years in the ]/], but when events span the start of the ]/], use AD or CE for the date at the end of the range (note that AD precedes the date and CE follows it). For example, <nowiki>]&ndash;]</nowiki> or <nowiki>]&ndash;]</nowiki>.


{{Shortcut|MOS:TIME|MOS:AMPM}}
*In articles about prehistory, if you use BP (]) or MYA (]), expand these abbreviations when you first use them, as most readers will be unfamiliar with them.


Context determines whether the ] or ] clock is used. In all cases, colons separate hours, minutes, and (where present) seconds, e.g. {{xt|1:38:09{{nbsp}}pm}} or {{xt|13:38:09}}. Use figures ({{xt|11{{nbsp}}a.m.}} or {{xt|12:45{{nbsp}}p.m.}}) rather than words ({{!xt|twelve forty-five p.m.}}).
*When either of two styles are acceptable it is inappropriate for a Misplaced Pages editor to change from one style to another unless there is some substantial reason for the change. For example, with respect to English spelling as opposed to American spelling it would be acceptable to change from American spelling to English spelling if the article concerned an English subject. Revert warring over optional styles is unacceptable; if the article is ] rather than ], it would be wrong to switch simply to change styles as both are acceptable. See also ].
* '''12-hour clock times''' end with lower-case {{xtn|a.m.}} or {{xtn|p.m.}}, or {{xtn|am}} or {{xtn|pm}}, preceded by a ], e.g. {{xt|2:30{{nbsp}}p.m.}} or {{xt|2:30{{nbsp}}pm}} (markup: <code>2:30{{tl|nbsp}}p.m.</code> or <code>2:30{{tl|nbsp}}pm</code>), not {{!xt|2:30p.m.}} or {{!xt|2:30pm}}. Hours should not have a leading zero (e.g. {{xt|2:30{{nbsp}}p.m.}}, not {{!xt|02:30{{nbsp}}p.m.}}). Usually, use {{xt|noon}} and {{xt|midnight}} rather than {{!xt|12 pm}} and {{!xt|12 am}}; whether "midnight" refers to the start or the end of a date should be explicitly specified unless clear from the context. Where several times that are all a.m. or all p.m. appear in close proximity, then ''a.m.'' or ''p.m.'' need be given only once if there is no risk of confusion.
* '''24-hour clock times''' have no a.m., p.m., noon or midnight suffix, and include a colon ({{xt|15:30}} not {{!xt|1530}}). Hours under 10 should have a leading zero ({{xt|08:15}}). The time {{xt|00:00}} refers to midnight at the start of a date, {{xt|12:00}} to noon, and {{xt|24:00}} to midnight at the end of a date, but {{!xt|24}} should not be used for the first hour of the next day (e.g. use {{xt|00:10}} for ten minutes after midnight, not {{!xt|24:10}}).


===Different calendars=== ====Time zones====
You can give dates in any appropriate calendar, as long as you also give the date in either the ] or ], as described below. For example, an article on the early ] may give dates in both the ] and the ].


{{shortcut|MOS:TIMEZONE}}
* Current events should be given in the Gregorian calendar.
Give dates and times appropriate to the ] where an event took place. For example, the date of the ] should be December{{nbsp}}7, 1941 (Hawaii time/{{zwsp}}date). Give priority to the place at which the event had its most significant effects; for example, if a hacker in Monaco attacked a Pentagon computer in the US, use the time zone for the Pentagon, where the attack had its effect. In some cases, the best solution may be to add the date and time in ] (UTC). For example:
* Dates before the adoption of the Gregorian calendar on ]-] should usually be given in the Julian calendar. The Julian day and month should not be converted to the Gregorian calendar, but the start of the ] should be taken to be ] (see below for more details).
* Dates of events in countries using the Gregorian calendar should be given in the Gregorian calendar. This includes much of ] from 1582, the ] from ]-], ] from ]-], and so on (see the ] article).


{{in5}}{{xt|8{{nbsp}}p.m. ] on January{{nbsp}}15, 2001 (01:00{{nbsp}}UTC, January{{nbsp}}16)}}
Other dates are ambiguous. Your options for this period are:
* Give the dates in the Julian calendar only. This means that the dates will match the dates in the primary sources for that period. If you do this you should indicate that the dates are in the Julian calendar.
* Convert the dates to the Gregorian calendar. This means that events in different countries can be correlated.
* Give dates in both calendars, for example, ''] died on ]-] (])/]-] (New Style).''


Alternatively, include just the ]:
At some places and times, dates other than ] were used as the start of the year. The most commonly encountered convention is the ''Annunciation Style'' used in Britain and its colonies in which the year started on ]. See the ] article for a list of other styles. You should always convert dates so that they correspond with years starting on ]. If it is important to preserve consistency with primary sources, you may give the date in the original style, but then you must also give the date in the modern style. For example, ''] died on ]-] (])/]-] (New Style).'' Although this would correspond to 3 April 1603 if fully converted into the Gregorian calendar, the month and day of a British event are normally not converted.


{{in5}}{{xt|21:00{{nbsp}}] (]) on 27{{nbsp}}July 2012}}
==Times==
===Time formatting===
Context shall determine whether the ] or ] clock notation should be used. In either case, the colon is used to separate hours, minutes and seconds.


Rarely, the time zone in which an event took place has since changed; for example, China until 1949 was divided into ], whereas all of modern China is one time zone; ]. Similarly, the term "UTC" is not appropriate for dates before this system was adopted in 1960;<ref>{{cite book |id=CCTF/09-32 |title=Coordinated Universal Time (UTC) |date=June 2, 2009 |publisher=] |page=3 |quote=This coordination began on January 1, 1960, and the resulting time scale began to be called informally 'Coordinated Universal Time.'&thinsp; |url= https://www.bipm.org/documents/20126/28435864/working-document-ID-3644/2a6ce17c-7b50-4164-9bee-64f77bfad895 |format=PDF |access-date=October 5, 2022}}</ref> ] (UT) is the appropriate term for the mean time at the ] when it is unnecessary to specify the precise definition of the time scale. Be sure to show the UTC or offset appropriate to the clock time in use at the time of the event, not the modern time zone, if they differ.
Times in the 12-hour clock end with lower case "a.m." or "p.m." These suffixes generally cannot be omitted, except that "noon" and "midnight" should be used instead of "12 p.m." and "12 a.m." respectively; some readers find the latter ambiguous. Beware that even "12 midnight" does not unambiguously distinguish between ] at the start and end of a given date.


<span id="Day, month and season names"></span><span id="Longer periods"></span><span id="Other periods"></span><span id="Other"></span>
24-hour clock times have no a.m./p.m./noon/midnight suffix. Discretion may be used to determine if the hour has a leading zero. 00:00 refers to midnight at the start of a day and 12:00 refers to noon. (In addition, 24:00 can be used for midnight at the end of a given date, which can be useful to state the end of a time interval.)
===Days of the week===
* Where space is limited (e.g. tables), days of the week may be abbreviated as {{xt|Sun}}, {{xt|Mon}}, {{xt|Tue}}, {{xt|Wed}}, {{xt|Thu}}, {{xt|Fri}}, {{xt|Sat}} (without dots, i.e. not {{!xt|Sun'''.'''<!--bolding to make dots more obvious-->}}, {{!xt|Mon'''.'''}}, etc.).


===Seasons of the year<span id="Seasons"></span>===
Examples:
{| class=wikitable
!width=100| 12-hour clock !!width=100| Not !!width=100| 24-hour clock !!width=100| Not
|-
|2 p.m. || 2pm || 14:00 || 14.00
|-
|2:34 p.m. || 2.34 PM || 14:34 || 1434
|-
|12:04:38 a.m. || 12.04 38″ A.M. || 00:04:38 or 0:04:38
|-
|noon ||12 noon || 12:00
|}


<!--Misplaced Pages:Manual of Style/Words to watch#Relative time references links to this section.-->{{shortcut|MOS:SEASON}}
===Time zones===
* Avoid using seasons to refer to a particular time of year, as they are often unduly ambiguous: {{!xt|Spring 1995}} began in the Southern Hemisphere six months after it did in the Northern Hemisphere; winter spans two calendar years in the Northern Hemisphere, but not in the Southern Hemisphere. Moreover, areas near the Equator have only ] and ]s. Unambiguous alternatives include {{xt|early{{nbsp}}1995}}; {{xt|the second quarter of 1995}}; {{xt|March to June{{nbsp}}1995}}; {{xt|spent the southern autumn in Antarctica}}.
When writing a date, first consider ''where'' the event happened and use the time zone there. For example, the date of the ] should be ], ] (Hawaii time/date). If it is difficult to judge ''where'', consider what is significant. For example, if a vandal based in Japan attacked a Pentagon computer in the United States, use the time zone for the Pentagon, where attack had its effect.
** Referring to a season by name is appropriate when it is part of a conventional name or designation ({{xt|annual mid-winter festival}}; {{xt|the autumn harvest}}; {{xt|the court's winter term}}; {{xt|the magazine's summer 2015 issue}}).
* Season names are generally not capitalized ({{xt|a hot summer}}), except when personified ({{xt|Old Man Winter}}) or when part of a formal name ({{xt|2018{{nbsp}}Winter Olympics}}; {{xt|Arab Spring}}) that is capitalized under the ]. They are capitalized when part of the title of a work ({{xt|''Science Fiction Quarterly'', Summer 1942}}), except that seasonal editions may be lower-cased in running text ({{xt|the Summer 1985 issue of ''Interzone''}} or {{xt|the summer 1985 issue of ''Interzone''}}).


===Decades===
If you know it, include the ] date and time of the event in the article, indicating that it is UTC.

{{shortcut|MOS:DECADE|MOS:DECADES}}
* To refer to a decade as a chronological period {{lang|la|per se}} (not with reference to a social era or cultural phenomenon), always use four digits and an ''s'', as in {{xt|the{{nbsp}}1980s}}. Do not use {{!xt|the{{nbsp}}1980's}}, or {{!xt|the{{nbsp}}1980{{nbh}}ies}}.
** Prefixes should be hyphenated ({{xt|the{{nbsp}}mid{{nbh}}1980s}};{{nbsp}} {{xt|pre{{nbh}}1960s social attitudes}}).<!--Non-breaking hyphens {{nbh}} are used in some examples to keep them from being fragmented over linebreaks here in MOS; that's not to say {{nbh}} ought to be used in "real life" in such situations.-->
** Adjectives should not be hyphenated ({{xt|the late 1950s, the early 1970s}}).
* For a social era or cultural phenomenon associated with a particular decade:
** Two digits (with a preceding apostrophe) may be used as an alternative to four digits, but only in well-established phrases seen in reliable sources: {{xt|the{{nbsp}}Roaring{{nbsp}}'20s}}; {{xt|the{{nbsp}}Gay{{nbsp}}'90s}}; {{xt|condemning the '60s counterculture}}{{mdash}}but {{xt|grew up in 1960s Boston, moving to Dallas in{{nbsp}}1971}}. Do not write: {{!xt|the{{nbsp}}90's}}; {{!xt|the{{nbsp}}90s}}; or {{!xt|the{{nbsp}}90s'}}.
** Another alternative (where seen in reliable sources) is to spell the decade out, capitalized: {{xt|changing attitudes of the Sixties}}.

===Centuries and millennia<span id="centuries"></span><span id="millennia"></span>===

{{shortcut|MOS:CENTURY|MOS:MILLENNIUM}}

The sequence of numbered years in dates runs {{xt|...{{nbsp}}2{{nbsp}}BC, 1{{nbsp}}BC, 1{{nbsp}}AD, 2{{nbsp}}AD{{nbsp}}...}}; there is no "]".
* Treat the 1st century AD as years {{nobr|1{{ndash}}100}}, the 17th century as {{nobr|1601{{ndash}}1700}}, and the second millennium as {{nobr|1001{{ndash}}2000}}; similarly, the 1st century BC{{\}}BCE was {{nobr|100{{ndash}}1}} BC{{\}}BCE, the 17th century BC{{\}}BCE was {{nobr|1700{{ndash}}1601}} BC{{\}}BCE, and the second millennium {{nobr|2000{{ndash}}1001}} BC{{\}}BCE.
* Centuries and millennia are identified using either Arabic numerals ({{nobr|{{xt|the 18th century}}}}) or words ({{xt|the second millennium}}), with in-article consistency (] notwithstanding). When used adjectivally they contain a hyphen ({{xt|nineteenth-century painting}} or {{xt|{{nobr|19th-century}} painting}}). Do not use superscripts ({{!xt|19<sup>th</sup> century}}).
* Do not capitalize ({{!xt|the best Nineteenth-century paintings}};{{nbsp}}{{!xt|during the Nineteenth Century}})
* Do not use ] ({{!xt|XVIII{{nbsp}}century}}).
* {{xt|The 18th century}} refers to the period ({{nobr|1701{{ndash}}1800}}), while strictly {{!xt|the 1700s}} refers either to ({{nobr|1700{{ndash}}1799}}) or ({{nobr|1700{{ndash}}1709}})
** When using forms such as {{xt|the 1900s}}, ensure there is no ambiguity as to whether the century or the decade is meant.
* {{crossref|See {{section link|WP:Manual of Style|En dashes}} for use of hyphens and dashes in obscure situations.}}

===Long periods of time<span id="Abbreviations for long periods of time"></span>===

* When the term is frequent, combine {{xtn|yr}}{{nbsp}}(years) or {{xtn|ya}}{{nbsp}}(years ago) with {{xtn|k}}{{nbsp}}(thousand): {{xtn|kya}}, {{xtn|kyr}}; {{xtn|M}}{{nbsp}}(million): {{xtn|Mya}}, {{xtn|Myr}}; and {{xtn|b}}{{nbsp}}(] billion): {{xtn|bya}}, {{xtn|byr}}. {{Crossref|(See {{section link|Year|Abbreviations yr and ya}} for more information.)}}
* In academic contexts, ]-based units are often used with an ]: {{xtn|ka}}{{nbsp}}(kiloannus), {{xtn|Ma}}{{nbsp}}(megaannus), and {{xtn|Ga}}{{nbsp}}(gigaannus). {{Crossref|(See {{section link|Year|SI prefix multipliers}} for more information.)}}
* Show the meaning parenthetically, and consider linking to the appropriate section of the ] article {{crossref|({{section link|Year|Abbreviations yr and ya}} or {{section link|Year|SI prefix multipliers}})}} on first occurrence and where the use is a standalone topic of interest. In source quotations, use square brackets: {{xt|"a potassium-argon date of 35.1{{nbsp}}Mya {{nbsp}}..."}}


==Numbers== ==Numbers==
{{redirect-distinguish|MOS:FIGURE|MOS:IMAGE}}
===Numbers===
<!-- see Talk page discussion on this subject before making changes.
-->
Very large numbers may be ] every three places (e.g.: 2,900,000), starting from the decimal separator in both directions. (This is different from the ]/] notation style, where ]s are not used, but as an option, a non-breaking ] may be inserted every three places.) In scientific contexts, ] is preferred. Large round numbers are generally assumed to be approximations; it is necessary to qualify with "about" or a similar term where the statement would otherwise be misleading.


===Numbers as figures or words===
A period (".") must be used as the ], separating the integer part from the fractional part.


{{shortcut|MOS:NUMERAL|MOS:SPELL09|MOS:MILLION|MOS:BILLION|MOS:TRILLION|MOS:LAKH|MOS:CRORE}}
For numbers between minus one and plus one, include the leading 0 ("0.02", not ".02").
{{crossref|Information on specific situations is scattered elsewhere on this page.}}


'''Generally, in article text:'''
The minus sign has two representations. One is the normal ''hyphen-minus'' ("-") available on every ] (twice on those with numeric keypad); the other ("&minus;") is most easily entered as <code>&amp;minus;</code>.
* Integers from zero to nine are spelled out in words.
* Integers greater than nine {{em|expressible in one or two words}} may be expressed either in numerals or in words ({{xt|16}} or {{xt|sixteen}}, {{xt|84}} or {{nobr|{{xt|eighty-four}}}}, {{xt|200}} or {{nobr|{{xt|two hundred}}}}). When written as words, integers from 21 to 99 that are not multiples of 10 are hyphenated (including when part of a larger number): {{nobr|{{xt|fifty-six}}}} and {{nobr|{{xt|fifty-six thousand}}}}, but {{xt|five{{nbsp}}hundred}} and {{xt|five{{nbsp}}thousand}}.


{{anchor|Numeral notes}}{{shortcut|MOS:NUMNOTES}}
===Percentages===
'''Notes and exceptions:'''
*The word ''percent'' or ''per cent'' is commonly used to indicate percentages in the body of an article. The symbol ''%'' may be more common in scientific or technical articles, or in complex listings. Be consistent throughout an article.
* Avoid beginning a sentence with a figure:
*Use the symbol ''%'' with a numeral for a percentage in such locations as ]s and ]es. There is no space between the numeral and the symbol %.
** Use: {{nowrap|{{xt|There were many matches''';''' 23 ended in a draw.}}}} Or: {{nowrap|{{xt|There were many matches'''.''' Twenty-three ended in a draw.}}}}
** Not: {{!xt|There were many matches'''.''' 23 ended in a draw.}}
<!--* Avoid spelling out the year, unless it is part of a title: **Not: {{nowrap|{{!xt|Ninteen hundred and fifty had no elections}}{{ndash}}}}-->
** Use: {{xt|No elections were held in 1945 and 1950.}}
** Not: {{nowrap|{{!xt|1945 and 1950 had no elections.}}}} (Nor: {{nowrap|{{!xt|Nineteen forty-five and 1950 had no elections}}{{mdash}}}}comparable numbers near one another should all be written in words or all in figures.)
* In tables and infoboxes, quantities are expressed in figures ({{xt|Years in office:{{nbsp}}5}}); but numbers within a table's explanatory text and comments follow the general rule.
* Numbers in mathematical formulae are never spelled out ({{nobr|{{xt|3 < π < {{sfrac|22|7}}}}}} not {{nobr|{{!xt|three < pi < twenty-two sevenths}}}}), and "numbers as numbers" are rarely spelled out in other mathematical contexts ({{xt|the first three primes are 2, 3, and 5}} not {{!xt|the first three primes are two, three, and five}}; but {{xt|zero-sum game}} and {{xt|roots of unity}}).<!--There's probably still work to be done on the "in other mathematical contexts" bit-->
* Sport scores and vote tallies should be given as numerical figures ({{xt|a {{nowrap|25–7}} victory}}; {{xt|passed with 7 ayes, 2 nays, and 1 abstention}}, though {{xt|passed with 7 ayes, 2 nays, and no abstentions}} would be acceptable, instead of {{xtn|...{{nbsp}}0 abstentions}}).
* Comparable values near one another should be all spelled out or all in figures, even if one of the numbers would normally be written differently: {{xt|patients' ages were five, seven, and thirty-two}} or {{xt|ages were{{nbsp}}5, 7, and{{nbsp}}32}}, but not {{!xt|ages were {{nobr|five, seven, and 32}}}}.<!--example using ages was chosen specifically, since questions about how to represent ages come up perennially-->
**Similar guidance applies where "mixed units" are used to represent a single value (as is often done with time durations, and in the imperial and US customary systems): {{xt|{{nobr|5 feet 11 inches}} tall}}; {{xt|{{nobr|five feet eleven inches}} tall}}; {{xt|{{nobr|3 minutes 27 seconds}}}}; {{xt|{{nobr|three minutes twenty-seven seconds}}}}.
* Adjacent quantities not comparable should ideally be in {{em|different formats:}} {{nobr|{{xt|twelve 90-minute volumes}}}} or {{nobr|{{xt|12 ninety-minute volumes}}}}, not {{nobr|{{!xt|12 90-minute volumes}}}} or {{nobr|{{!xt|twelve ninety-minute volumes}}}}.
** Avoid awkward juxtapositions: {{xt|On February 25, 2011, twenty-one more were chosen}}, not {{nobr|{{!xt|On February 25, 2011, 21 more were chosen}}}}.
* Sometimes figures and words carry different meanings; for example, {{xt|Every locker except one was searched}} implies there is a single exception (without specifying which), while {{xt|Every locker except{{nbsp}}1 was searched}} implies that locker number{{nbsp}}1 was the only locker not searched.
* Proper names, technical terms, and the like are never altered: ],{{nbsp}} ],{{nbsp}} ],{{nbsp}} ],{{nbsp}} '']'',{{nbsp}} ],{{nbsp}} ],{{nbsp}} '']'',{{nbsp}} ],{{nbsp}} ],{{nbsp}} '']'',{{nbsp}} "]".
* Figures as figures: Use a figure when the figure itself (its ], shape, etc.) is meant: {{xt|a figure-8 pattern}}; {{xt|in the shape of the numeral ''6''}}. {{crossref|(See {{section link|Misplaced Pages:Manual of Style/Text formatting#Words as words}}.)}}
* Only figures are used with unit {{em|symbols}} ({{xt|12 min}} not {{!xt|twelve min}}); but figures or words may be used with unit {{em|names}} ({{xt|12 minutes}} or {{xt|twelve minutes}}), subject to the provisions above.


'''Other numbers'''
===Numbers in words===
* Other numbers are given in numerals ({{xt|3.75}}, {{xt|544}}) or in forms such as {{xt|21{{nbsp}}million}} (or ''billion'', ''trillion'', etc.{{snd}}but rarely ''thousand'' or ''hundred''). Markup: {{nowrap|<code><nowiki>21{{nbsp}}million</nowiki></code>}}
*Whole numbers from zero to ten should be spelled out as words in the body of an article. Use numerals in ]s and ]es.
** ''Billion'' and ''trillion'' are understood to represent their ] values of 10<sup>9</sup>{{nbsp}}(1,000,000,000) and 10<sup>12</sup>{{nbsp}}(1,000,000,000,000), respectively. Keep this in mind when translating articles from non-English or older sources.
** {{xt|M}} (unspaced, capitalized) or {{xt|bn}} (unspaced), respectively, may be used for "million" or "billion" after a number, when the word has been spelled out at the first occurrence ({{xt|Her estate of &pound;61{{nbsp}}million was split among her husband (&pound;1M), her son (&pound;5M), her butler (&pound;10M), and her three Weimaraners (&pound;15M each).}}).<!--This needs to be coordinated with text in units tables re nonuse of M (for 1000) MM, etc.-->
** SI prefixes and symbols, such as {{xtn|mega-}}{{nbsp}}({{xtn|M}}), {{xtn|giga-}}{{nbsp}}({{xtn|G}}) and {{xtn|tera-}}{{nbsp}}({{xtn|T}}), should be used only with units of measure as appropriate to the field and not to express large quantities in other contexts. Examples of misuse: {{!xt|In a population of 1.3G{{nbsp}}people, 300{{nbsp}}megadeaths would be expected.}}
** Sometimes, the ] used in an article may suggest the use of a numbering system other than the Western thousands-based system. For example, the ] is conventionally used for certain things (especially monetary amounts) in ]. This is discouraged in Misplaced Pages articles by {{section link|WP:Manual of Style#Opportunities for commonality}}.
*** When it is done anyway, for contextually important reasons, link the first spelled-out instance of each quantity (e.g. <code><nowiki>]</nowiki></code>, which yields: ]). If no instances are spelled out, provide a note after the first instance, directing the reader to the article about the numbering system.
*** Provide a conversion to Western numbers for the first instance of each quantity (For Indian figures, the templates {{tlx|lakh}} and {{tlx|crore}} may be used for this purpose), and provide conversions for subsequent instances if they do not overwhelm the content of the article. For example, write {{xt|three ] (thirty million)}}. When converting a currency amount, use the exchange rate that applied at the time being written about; the {{tlx|FXConvert}} template can be used for this purpose, or specialized templates for a currency such as {{tlx|INRConvert}} (for Indian Rupees) or {{tlx|KRWConvert}} (for Korean Won) can be used.
*** Group digits in Western thousands-based style (e.g., {{xt|30,000,000}}; not {{!xt|3,00,00,000}}); {{crossref|see {{section link||Delimiting (grouping of digits)}}, below}}.
*** An article's variety of English does not uniquely determine its formatting of numbers. Other considerations{{snd}}such as conventions used in mathematics, science, and engineering{{snd}}may also apply. In general, choice and order of formats and conversions is a matter of editorial discretion and consensus at the article.


{{shortcut|MOS:ORDINAL}}<!--Positioned before (rather than after) section in question to avoid crash of shortcut boxes when sections are short.-->
*Numbers above ten may be written out if they are expressed in two or fewer words, except in tables and infoboxes. Example: "sixteen", "eighty-four", "two hundred", "twenty million" ''but'' "3.75", "544", "21 million".


===Ordinals===
*Proper names and formal numerical designations should instead comply with common usage. Example: '']'', ''4 Main Street'', '']'', ''channel 6''.


{{anchor|1st|1ST}}
*Within a context or a list, style should be consistent. Example: ''There were 5 cats, 12 dogs, and 32 birds.'' or ''There were five cats, twelve dogs, and thirty-two birds.''
{{redirect|MOS:1ST|the guideline on the first sentence in articles|MOS:FIRST}}
* The general principles set out in {{section link||Numbers as figures or words}} apply to ordinals. In particular, do not start a sentence with a figure, and generally use {{xt|first}} through {{xt|ninth}}, not {{!xt|1st}} through {{!xt|9th}}, for single-digit ordinals.
* In "suffix" forms, use two-letter suffixes: {{xt|1st, 2nd, 3rd, 4th}} and so on ({{xt|2nd{{nbsp}}Battalion}} not {{!xt|2d{{nbsp}}Battalion}}). Do not superscript (e.g. {{!xt|123<sup>rd</sup>}}).
* Do not use ordinals for dates (see ]).
* In English text, do not use a dot ({{!xt|.}}) or the ] ({{!xt|º}}). The masculine {{xt|º}} or feminine {{xt|ª}} ordinal indicator is acceptable in names, quotations, etc. from languages that conventionally use it. An Italian example: {{xt|{{lang|it|313º Gruppo Addestramento Acrobatico}}}} not {{!xt|313º Acrobatic Training Group}} or {{!xt|the 313º}}. Use HTML markup for languages that do not have a special character but conventionally use a superscript, like {{xt|{{lang|fr|2<sup>e</sup>}}}} in French.
* ]s are normally written with ASCII ]s (without suffix, e.g. {{xt|Elizabeth II}} not {{!xt|Elizabeth IInd}} or {{!xt|Elizabeth 2nd}}).


===Number ranges===
*It is considered awkward for a numeral to be the first word of a sentence: recast the sentence or spell the number out.


{{shortcut|MOS:NUMRANGE|MOS:PAGERANGE}}
*Fractions standing alone should be spelled out unless they occur in a percentage. If fractions are mixed with whole numbers, use numerals.


Like {{crossref|]}}, number ranges and page ranges should state the full value of both the beginning and end of the range, separated by an ]: {{xt|pp.{{nbsp}}1902{{ndash}}1911}} or {{xt|entries{{nbsp}}342{{ndash}}349}}. Except within quotations, avoid abbreviated forms such as {{!xt|1902{{ndash}}11}} or {{!xt|342{{ndash}}9}}, which are not understood universally, are sometimes ambiguous, and can cause inconsistent metadata to be created in citations.
*] is understood as 10<sup>9</sup> in the United States, English Canada and most of the rest of the English-speaking world. (In most ] and ]s, it means 10<sup>12</sup>.) See the detailed discussion in ], ]. International monetary institutions generally recognize a billion as equaling 10<sup>9</sup> when it relates to expenditure, GDP, deficits.


===Sport scores, vote tallies, etc.===
===Natural number===
{{shortcut|MOS:VOTE|MOS:SCORES}}
'']'' has two meanings:
* positive integer, or
* non-negative integer (including zero).


Sport scores, vote tallies, or other presentations that juxtapose two opposing quantities use an unspaced en dash:
When referring to such numbers, explicitly use one of the above phrases rather than "natural numbers", unless it does not matter which interpretation is chosen.
*{{xt|Smith beat Jones {{nowrap|7{{ndash}}3}}.}}
*{{xt|Polls predicted Alice would defeat Bob {{nowrap|74{{ndash}}20}} percent, with 6 percent undecided.}}
To avoid potential line breaks, use {{tlx|nowrap}} around the entire score construction, or use {{tlx|nbnd}} instead of {{tlx|ndash}}.


===Ranges=== ===Singular versus plural===
Sometimes numbers and dates are expressed in ranges, such as "14–17" for the numbers 14 to 17. It is often preferable to write this out—for example, "from 14 to 17" or "fourteen through seventeen"—to avoid confusion with "fourteen minus seventeen", which is expressed with spaces, as "14 <code>&amp;minus;</code> 17".


* Nouns following ] are singular ({{xt|took {{frac|4}} dose}};{{nbsp}} {{xt|net change was −{{frac|2}} point}};{{nbsp}} {{xt|{{frac|3|2}} dose}}).
Traditionally, ranges of numbers and dates are given with an en dash (type <code>&amp;ndash;</code> or click the – button below the edit window). Therefore, many Wikipedians support using this style exclusively. However, some sources now use spaced or unspaced hyphens, at least online, and some Wikipedians believe that these hyphens should not be changed to en dashes.
* Nouns following ]s are plural ({{xt|1{{frac|1|2}} doses}};{{nbsp}} {{xt|another 4{{frac|3|4}} miles}}).
* Nouns following the lone, unsigned digit 1 (one) are singular, but those following other decimal numbers (i.e. base-10 numbers not involving fractions) are plural ({{xt|increased 0.7 percentage points}};{{nbsp}} {{xt|365.25{{nbsp}}days}};{{nbsp}} {{xt|paid 5 dollars per work hour, 1 dollar per travel hour, 0 dollars per standby hour}};{{nbsp}} {{xt|increased by 1{{nbsp}}point}} but {{xt|net change +1{{nbsp}}points}};{{nbsp}} {{xt|net change &minus;1{{nbsp}}points}};{{nbsp}} {{xt|net change 1.0{{nbsp}}points}}).
* The same rules apply to numbers given in words ({{xt|one dose}};{{nbsp}} {{xt|one and one-half doses}};{{nbsp}} {{xt|zero dollars}};{{nbsp}} {{xt|net change of negative one points}}).


===Fractions and ratios<span id="Fractions"></span>===
See ] for more information.


{{shortcut|MOS:FRAC|MOS:RATIO}}
===Non-base-ten notations===
* Where numerator and denominator can each be expressed in one word, a fraction is usually ] (e.g. {{xt|a two-thirds majority}}; {{nbsp}}{{xt|moved one-quarter mile}}); use figures if a fraction appears with a unit symbol (e.g. {{xt|{{frac|1|4}}{{nbsp}}mi}} (markup: <code>{{tlf|frac|1|4}}&amp;nbsp;mi</code>), not {{!xt|a quarter of a mi}} or {{!xt|one-quarter mi}}). A common exception is a series of values: {{xt|The distances were {{frac|1|1|4}}, {{frac|2|3}} and {{frac|1|2}} mile, respectively}}.
For numbers expressed in ] other than base ten:
* ] may be given in figures or words (perhaps applying the guidance ] to the integer part). If given in figures, they are unspaced (not {{!xt|Platform 9{{nbsp}}{{frac|3|4}}}} or {{!xt|Platform 9-{{frac|3|4}}}} but {{xt|Platform {{frac|9|3|4}}}} (markup: <code><nowiki>{{frac|9|3|4}}</nowiki></code>)). In any case the integer and fractional parts should be consistent (not {{!xt|Platform nine and{{nbsp}}{{frac|3|4}}}}).
*In computer-related articles, use the ] prefixes '''0x''' (zero-ex) for hexadecimal and '''0''' (zero) for octal. <!-- Note that 0b is *not* a valid C prefix --> For binary, use '''0b'''. It may be a good idea to include a note at the top of the page about these prefixes.
* Metric (SI) measurements generally use decimals, not fractions ({{xt|5.25{{nbsp}}mm}}, not {{!xt|5{{frac|1|4}}{{nbsp}}mm}}).
*In all other articles, use subscript notation. For example: 137<sub>9</sub>, 241<sub>6</sub>, 2A9<sub>12</sub>, A87D<sub>16</sub> (use &lt;sub> and &lt;/sub>).
* Non-metric (imperial and US customary) measurements may use fractions or decimals ({{xt|5{{frac|1|4}}{{nbsp}}inches}};{{nbsp}}{{xt|5.25{{nbsp}}inches}}); the practice of reliable sources should be followed, and within-article consistency is desirable.
*For base eleven and higher, use whatever symbols are conventional for that base. A common convention is to use A&ndash;Z for digits ten to thirty-five. Where letters are present, use uppercase: 0x5AB3, not 0x5ab3.
* In science and mathematics articles, mixed numbers are rarely used (use {{xt|{{sfrac|4|3}} the original voltage}} rather than {{!xt|1{{sfrac|1|3}} times the original voltage}}). The use of {{tlx|frac}} ]; instead use one of these styles:
** <math>\textstyle\frac{1}{2}</math> (markup: <code><]>\textstyle\frac{1}{2}<nowiki></math></nowiki></code>)
** {{xt|{{sfrac|1|2}}}} (markup: {{tlx|sfrac|1|2}})
** {{xt|1/2}} (markup: <code>1/2</code>)
* Do not use ] characters such as {{!xt|½}} (deprecated markup: {{!mxt|&amp;frac12;}} or {{!mxt|&amp;#189;}}).{{efn|Some precomposed fractions may not work with screen readers, and not all fractions are available precomposed.}}
** Except: If ¼, ½, and ¾{{efn|These three characters are in ] and work in screen readers.}} are the only fractions needed, they may be used in an article, or category name, maintaining typographical consistency within an article where possible. (Examples: ], ], ], ].) <!-- In case consensus changes or there is an usual corner case, {{DISPLAYTITLE:{{NAMESPACE}}:Ranma <sup>1</sup>/<sub>2</sub>}} works for e.g. ]. -- Beland -->
** For other fractions, where templates cannot be used due to technical limitations, use the ASCII representation with spaces. For example, ].
* Ordinal suffixes such as {{xtn|-th}} should not be used with fractions expressed in figures (not {{!xt|each US state has 1/50th of the ] votes}}; {{!xt|1/8th mile}}, but {{xt|one-fiftieth of the ] votes}}; {{xt|1/8 mile}}; {{xt|one-eighth mile}}).
* For dimensionless ratios (i.e. those without accompanying units), place a colon between integers, or place ''to'' between numbers-as-words: {{ xt|favored by a 3:1 ratio}} or {{nobr|{{xt|a three-to-one ratio}}}}, not {{nobr|{{!xt|a 3/1 ratio}}}} or {{nobr|{{!xt|a 3{{ndash}}1 ratio}}.}} The same style is used to express ] in sport, gambling, and other statistical predictions.
** Use a colon (spaced) when one or more decimal points is present {{nobr|({{ xt|a 3.5{{nbsp}}:{{nbsp}}1 ratio}} (markup:}} {{nobr|<code>a 3.5&amp;nbsp;:&amp;nbsp;1 ratio</code>)).}}
** Do not use the colon form where units are involved ({{!xt|dissolve using a {{nobr|3 ml : 1 g ratio}}}}){{mdashb}}instead see ''ratios'' section of table at ], below.
{{see also|Misplaced Pages:Manual of Style/Mathematics#Fractions}}

===Decimals<span id="Decimal points"></span>===

{{shortcut|MOS:DECIMAL}}
* Use a period/full point (<code>.</code>) as the ], {{em|never}} a comma: {{xt|6.57}}, not {{!xt|6,57}}.
* Numbers between −1 and +1 require a leading zero ({{xt|0.02}}, not {{!xt|.02}}); exceptions are sporting performance averages ({{xt|.430 ]}}) and conventional terms such as {{xt|.22{{nbsp}}caliber}}.
* Although repeating digits may be indicated with an ] (e.g. {{nowrap|<code><nowiki>14.31{{overline|28}}</nowiki></code>}} gives {{xt|14.31{{overline|28}}}}), users of screen readers will not hear any indication of the overbar. Apart from in mathematics articles, consider rounding to a reasonable resolution instead (e.g. a ] {{xt|1=≈£0.00052}} not {{!xt|1=£0.0005208{{overline|3}}}}, an ] {{xt|1=≈0.333 ]s}} not {{!xt|1=0.{{overline|3}} ]s}}), or showing initial repeats before the overbar (e.g. 0.33{{overline|3}}). If overbars are used, consider explaining the notation on first use. Do not write e.g. {{nobr|{{!xt|14.31(28)}}}} because it resembles ].

===Grouping of digits===
<span id="Delimiting (grouping of digits)"></span><span id="Grouping of digits"></span>
{{shortcut|MOS:DIGITS}}

* In general, digits should be grouped and separated either by commas or by narrow gaps ({{em|never}} a period/full point).
** Grouping with commas
*** Left of the decimal point, five or more digits are grouped into threes separated by commas (e.g. {{xt|12,200}}; {{xt|255,200{{nbsp}}km}}; {{xt|8,274,527th}}; {{xt|{{frac|86,400}}}}).
*** Numbers with exactly four digits left of the decimal point may optionally be grouped (either {{xt|1,250}} or {{xt|1250}}), consistently within any given article.
*** Do not use commas to the right of the decimal point, or with numbers not in base 10.
*** Markup: {{tlc|]}} produces this formatting.
** Grouping with narrow gaps
*** Digits are grouped both sides of the decimal point (e.g. {{xt|{{val|6543210.123456}}}}; {{xt|{{val|520.01234|u=degC}}}}; {{xt|{{sfrac|{{val|101325}}|760}}}}).
*** Digits are generally grouped into threes. Right of the decimal point, {{em|usual}} practice is to have a final group of four in preference to leaving an "orphaned" digit at the end ({{xt|{{val|99.1234567}}}}, but {{xt|{{gaps|99.123|456|7}}}} would also be acceptable). In mathematics-oriented articles long strings may be grouped into fives (e.g. {{xt|{{gaps|3.14159|26535|89793|23846|...}}}}).
*** This style is especially recommended for articles related to science, technology, engineering or mathematics, though in these contexts there may be cases in which grouping confuses rather than clarifies. (For example, for fractions written in horizontal format, adding spaces to a fraction like 123456/127 would cause it to be misread as 123{{sfrac|456|127}} or 1{{sfrac|23456|127}}.)
*** Markup: Templates {{tlx|val}} or {{tlx|gaps}} may be used to produce this formatting. Note that use of {{em|any}} space character as a separator<!--Word included here on purpose, for in-page searching.--> in numbers, including non-breaking space, is problematic for ]s. {{crossref|(See {{section link||Non-breaking spaces}}.)}} Screen readers read out each {{em|group}} of digits as separate numbers (e.g. <code>30{{tl|thin space}}000</code> is read as "thirty zero zero zero"). The output of {{tlx|val}} and {{tlx|gaps}} is compatible with screen readers.
* Delimiting style should be consistent throughout a given article.
** Either use commas or narrow gaps, but not both in the same article.
** Either group the thousands in a four-digit number or do not, but not mixed use in the same article.
** However, grouping by threes and fives may coexist.
* Four-digit page numbers and four-digit calendar years should never be grouped (not {{!xt|sailed in 1,492}}, but {{xt|dynasty collapsed around 10,400{{nbsp}}BC}} or {{xt|by {{val|13727|u=AD}}, Vega will be the northern pole star}}).

===Percentages===

{{shortcut|MOS:PERCENT|MOS:%}}
* Throughout scientific/{{zwsp}}technical articles, and in tables and infoboxes in ''any'' article, the symbol <code>%</code> is generally preferred. Omit space ({{xt|3%}}, not {{!xt|3{{nbsp}}%}}), and do not use mixed forms such as {{!xt|three{{nbsp}}%}}.
* The body{{efn|name=body}} of non-scientific/{{zwsp}}non-technical articles may use either the <code>%</code> symbol or the word(s) {{xtn|percent}} (American English) or {{xtn|per{{nbsp}}cent}} (British English): {{xt|10 percent}}; {{xt|ten percent}}; {{xt|4.5 per cent}}.
* Ranges are written {{xt|10{{ndash}}12%}}, {{xt|ten to twelve per cent}}, or {{xt|ten to twelve percent}}; not {{!xt|ten{{ndash}}twelve per cent}}, {{!xt|10%{{ndash}}12%}}, or {{nobr|{{!xt|10 to 12%}}}}.
* When expressing the difference between two percentages, do not confuse a percentage change with a change in ]s.

===Scientific and engineering notation<span id="Scientific notation, engineering notation, and uncertainty"></span>===
{{Shortcut|MOS:SCIENGNOTATION|MOS:10^X}}
* ] always has a single nonzero digit to the left of the point: not {{!xt|{{val|60.22|e=22}}}}, but {{xt|{{val|6.022|e=23}}}}.
* ] is similar, but with the exponent adjusted to a multiple of three: {{xt|{{val|602.2|e=21}}}}.
* Avoid mixing scientific and engineering notations: {{!xt|A {{val|2.23|e=2|u=m2}} region covered by {{val|234.0|e=6|u=grains of sand}}}}.
* In a table column (or other presentation) in which all values can be expressed with a single power of 10, consider giving e.g. {{xt|{{e|7}}}} once in the column header, and omitting it in the individual entries. (Markup: <code><nowiki>{{e|7}}</nowiki></code>)
* In both notations, the number of digits indicates the precision. For example, {{xt|{{val|5|e=3}}}} means rounded to the nearest thousand; {{xt|{{val|5.0|e=3}}}} to the nearest hundred; {{xt|{{val|5.00|e=3}}}} to the nearest ten; and {{xt|{{val|5.000|e=3}}}} to the nearest unit.

Markup: {{tlx|val}} and {{tlx|e}} may be used to format exponential notation.

===Uncertainty and rounding <span id="Uncertainty"></span> <span id="Large numbers"></span>===

{{shortcut|MOS:UNCERTAINTY|MOS:LARGENUM}}
* Where explicit uncertainty information (such as a ]) is available and appropriate for inclusion, it may be written in various ways:
** {{xt|(1.534 ± 0.035) × 10<sup>23</sup> m}}
** {{xt|12.34{{nbsp}}m<sup>2</sup> ± 5%}} (not used with scientific notation)
** {{xt|15.34 {{su|p=+0.43|b=−0.23}} × 10<sup>23</sup> m}}
** {{xt|1.604(48) × 10<sup>−4</sup> J}} (equivalent to {{xt|(1.604 ± 0.048) × 10<sup>−4</sup> J}}){{efn|1=The number in parentheses in a construction like {{xt|1.604(48) × 10<sup>−4</sup> J}} is the numerical value of the standard uncertainty referred to the corresponding last digits of the quoted result.<ref>{{cite web |url= http://www.physics.nist.gov/cgi-bin/cuu/Info/Constants/definitions.html |title=Fundamental Physical Constants: Standard Uncertainty and Relative Standard Uncertainty |work=The NIST Reference on Constants, Units, and Uncertainty |date=June 25, 2015<!--Last updated, according to https://physics.nist.gov/cuu/Constants/bibliography.html --> |publisher=US ] |access-date=December 12, 2017}}</ref>}}
** {{xt|Polls estimated Jones's share of the vote would be 55 percent, give or take about 3 percent}}
** Markup: {{tlx|+-}}, {{tlx|su}}, and {{tlx|val}} may be used to format uncertainties.
* Where explicit {{em|uncertainty is unavailable}} (or is unimportant for the article's purposes), round to an appropriate number of ]s; the precision presented should usually be conservative. Precise values (often given in sources for formal or matter-of-record reasons) should be used only where stable and appropriate to the context, or significant in themselves for some special reason.
** {{xt|The speed of light is defined to be 299,792,458{{nbsp}}m/s}}
** {{em|but}} {{xt|Particle velocities eventually reached almost two-thirds the 300-million-metre-per-second speed of light.}}
** {{xt|checks worth $250 (equivalent to $1,800 in 2016)}} (not {{!xt|$1,845.38 in 2016}})
** {{xt|The city's 1920 population was 10,000}} (not {{!xt|population was 9,996}}{{snd}}an official figure unlikely to be accurate at full precision)
** {{em|but}} {{xt|The town was ineligible because its official census figure (9,996) fell short of the statutory minimum of ten thousand }} (unusual case in which the full-precision official figure is truly informative)
** {{xt| The accident killed 337 passengers and crew, and 21 people on the ground }} (likely that accurate and precise figures were determined)
** {{xt| At least 800 persons died in the ensuing mudslides }} (unlikely that any precise number can be accurate, even if an official figure is issued)
** {{em|or}} {{xt| Officials listed 835 deaths, but the Red Cross said dozens more may have gone unreported }} (in reporting conflicting information, give detail sufficient to make the contrast intelligible)
** {{xt|The jury's award was $8.5{{nbsp}}million}} (not {{!xt|$8,462,247.63}}). {{xt|The appeals court reduced this to $3,000,001 (one dollar in actual damages, the remainder in punitive damages).}}
* The number of decimal places should be consistent within a list or context ({{xt|The response rates were 41.0 and 47.4 percent, respectively}}, not {{!xt|41 and 47.4 percent}}), unless different precisions are actually intended.
* It may sometimes be appropriate to note the {{em|lack}} of uncertainty information, especially where such information is normally provided and necessary for full interpretation of the figures supplied.
** {{xt|A local newspaper poll predicted 52 percent of the vote would go to Smith, but did not include information on the uncertainty of this estimate}}
* The {{tlx|undue precision}} template may be added to figures appearing to be overprecise.
* Avoid using "approximately", "about", and similar terms with figures that have merely been approximated or rounded in a normal and expected way, unless the reader might otherwise be misled.
** {{xt|The tallest player was 6 feet 3 inches}} ({{nobr|not {{!xt|... about 6 feet 3 inches}}}}{{snd}}heights are conventionally reported only to the nearest inch, even though greater precision may be available in principle)<!--Please, no lectures about SI{{snd}}if you can give a parallel metric example please do so.-->
** {{em|but}} {{xt|The witness said the assailant was about 5 feet 8 inches tall}} ("about" because here the precise value is unknown, with substantial uncertainty)
* The reader may be assumed to interpret large round numbers ({{xt|100,000 troops}}) as approximations. Writing a quantity in words ({{xt|one hundred thousand troops}}), especially if the ] (''a''/''an'') is used instead of the word ''one'' ({{xt|a hundred thousand troops}}), can further emphasize its approximate nature.
* {{crossref|See {{section link||Unit conversions}} below for precision issues when converting units.}}

===Non–base-10 notations<span class="anchor" id="Non–base 10 notations"></span>===

{{shortcut|MOS:BASE|MOS:RADIX|MOS:BINARY|MOS:HEX}}
* In computer-related articles, use the prefix <code>0x</code> for hexadecimal and <code>0b</code> for binary,{{efn|1=The prefixes <code>0x</code> for hexadecimal and <code>0b</code> for binary have widespread support in systems programming languages including ], ], ], ] and ].}} unless there is a strong reason to use some other notation.{{efn|1=One such situation is with ] codepoints, which use <code>U+</code>; {{xt|U+26A7}}, not {{!xt|0x26A7}}.}} Explain these prefixes in the article's introduction or on first use.
* In all other articles, use {{tlx|base}}: {{base|137|9}}, {{base|201|3}}. Markup: <code><nowiki>{{base|137|9}}</nowiki></code>, <code><nowiki>{{base|201|3}}</nowiki></code>
* For ] above 10, use symbols conventional for that base (as seen in reliable sources) e.g. for ] use {{nobr|0{{ndash}}9 and A{{ndash}}F}}.
* For octal, use {{base|200|8}}. Avoid using a prefix unless it is needed for computer code samples, in which case explain the prefix on first use.

===Mathematical formulae===

{{Main|Misplaced Pages:Manual of Style/Mathematics}}

There are multiple ways to display mathematical formulae, covered in detail at {{section link|Misplaced Pages:Manual of Style/Mathematics#Typesetting of mathematical formulae}}. One uses special MediaWiki {{tag|math}} markup using ] syntax, which is capable of complex formulae; the other relies on conventionalized ] formatting of simple formulae.

The {{tag|math|o}} markup is displayed as a ] image by default. Logged-in users can optionally have it rendered in ], or in HTML (via ]); detailed instructions are at ].

].


==Units of measurement== ==Units of measurement==
Misplaced Pages articles are intended for people anywhere in the world. Try to make articles simple to read and translate.
* Conversions should generally be included and not be removed.
* The ] section of the ] states "For units of measure, use SI units as the main units in science articles, unless there are compelling historical or pragmatic reasons not to do so."
* If editors cannot agree about the sequence of units, put the source value first and the converted value second.
* If for some reason the choice of units is arbitrary, choose ] as the main unit, with other units in parentheses. For subjects dealing with the United States, it might be more appropriate to use U.S. measurements first, i.e. mile, foot, U.S. gallon.
* Spell out units in the text.
* Use digits and unit symbols for values in parentheses and for measurements in tables. For example, "a pipe 100&nbsp;millimetres (4&nbsp;in) in diameter and 16&nbsp;kilometres (10&nbsp;mi) long" '''or''' "a pipe 4&nbsp;inches (100&nbsp;mm) in diameter and 10&nbsp;miles (16&nbsp;km) long".
* Converted values should use a level of precision similar to that of the source value. For example, "the Moon is 380,000 kilometres (240,000&nbsp;mi) from Earth", not "(236,121&nbsp;mi)".
* Use standard abbreviations when using symbols. For example, metre is m, kilogram is kg, inch is in (not " or &Prime;), foot is ft (not ' or &prime;), and ] is lb (not #).
* Do not append an ''s'' for plurals of unit symbols/abbreviations. For example, kg, in, yd, lb, ''not'' kgs, ins, yds, lbs.
* Some non-metric units have more than one version. Be specific. For example, '']'' or '']'' rather than just ''gallon''. Similarly, use '']'' or '']'' rather than just ''mile'' in aviation, space, sea and in some other contexts.
* Put a space between the value and the unit symbol, for example "25&nbsp;kg" not "25kg". Preferably, use <code>&amp;nbsp;</code> for the space (<code>25&amp;nbsp;kg</code>) so that it does not break lines.
*Following ] or ] conventions, add a reference for numbers that identifies not only the source, but also the ''source's original units''.
*In a direct quotation, if the text includes an obscure use of units (e.g., five million board feet of lumber), annotate it with a footnote which provides metric units rather than changing the actual quotation.


{{Shortcut|MOS:UNIT|MOS:UNITS|MOS:METRIC|MOS:MEASUREMENT}}
===Examples===
* The highest score recorded for the Deuces High pinball game was 11,933,750.
* The ] stands ] (5&nbsp;ft) at the shoulders and weighs between ] (6,000&ndash;9,900&nbsp;lb).
** <code><nowiki>The ] stands ] (5&amp;nbsp;ft) at the shoulders and weighs between ] (6,000&amp;ndash;9,900&amp;nbsp;lb).</nowiki></code>
* … between ].
* The first sub-four-minute mile was run by ].
* The ] diameter projectile offers a wide range of options for battlefield usage.
* 10² = 100
** <code><nowiki>10&amp;sup2; = 100</nowiki></code>
** <code><nowiki>10² = 100</nowiki></code>
*A large number such as 156,234,000,000,000,000,000,000,000,000 can be concisely recorded as <code><nowiki>1.56234{{e|29}}</nowiki></code> (displays as 1.56234{{e|29}}), and a small number such as 0.0000000000234 can be written as <code><nowiki>2.34{{e|&minus;11}}</nowiki></code> (displays as 2.34{{e|&minus;11}}).
* The computer has a 160&nbsp;GB hard disk and 512&nbsp;] of RAM.


===Unit choice and order===
==Magnitude prefixes==
===Binary prefixes===
{{Quantities of bytes}}
In computing, ]es can be used to quantify large numbers where powers of two are more useful than powers of ten. They are commonly written and pronounced identically to the ]es, but each successive prefix is multiplied by 1024 (2<sup>10</sup>) rather than 1000 (10<sup>3</sup>).


Quantities are typically expressed using an appropriate "primary unit", displayed first, followed, when appropriate, by a conversion in parentheses e.g. {{xt|{{convert|200|km|mi}}}}. For details on when and how to provide a conversion, see the section {{section link||Unit conversions}}. The choice of primary units depends on the circumstances, and should respect the principle of ], where applicable:
===Avoiding confusion===
* In '''non-scientific articles with strong ties to the United States''', the primary units are ] (pounds, ], feet, inches, etc.)
Using the prefixes kilo-, mega-, giga-, etc., and symbols like kB, MB, GB, etc., in the binary sense can cause confusion.
* In '''non-scientific articles with strong ties to the United Kingdom''', the primary units for most quantities are metric or other internationally used units,{{efn|1=If there is disagreement about the primary units used in a UK-related article, discuss the matter on the article talk-page or at ] (]). If consensus cannot be reached, refer to historically stable versions of the article and retain the units used in these as the primary units. Also note the ] of British publications (e.g. , under "Metric").}} except that:
In January 1999, the ] proposed, as an addendum to ], the prefixes ''kibi-'', ''mebi-'', ''gibi-'', etc., and the symbols Ki, Mi, Gi, etc. to specify binary multiples of a quantity. The replacement abbreviations have since been recommended by groups in other organizations such as ] and ].
** UK engineering-related articles, including those on bridges and tunnels, generally use the system of units in which the subject project was ] (but road distances are given in imperial units, with a metric conversion{{snd}}see next bullet);
** the primary units for distance/{{zwsp}}length, speed and fuel consumption are ], miles per hour, and miles per imperial gallon (except for short distances or lengths, where miles are too large for practical use);
** the primary units for personal height and weight are feet{{zwsp}}/inches and stones/{{zwsp}}pounds;
** imperial pints are used for quantities of draught beer/{{zwsp}}cider and bottled milk;
* In '''all other articles''', the primary units chosen will be ] units (such as kilograms), ], or such other units as are conventional in reliable sources discussing the article topic (such as ] (rpm) for ], ] for heights of horses, ], etc.)
** the primary SI units for personal height and weight are centimetres and kilograms.


{{em|Special considerations:}}
*
* Quantities set via definition (as opposed to measured quantities) should be given first in the units used in the definition, even if this makes the structure of presentation inconsistent: {{xt|During metrication, the speed limit was changed from 30{{nbsp}}mph (48{{nbsp}}km/h) to 50{{nbsp}}km/h (31{{nbsp}}mph)}}.
*
** Or use ''about'' to emphasize which is the statutory, exact value: {{xt|...from 30{{nbsp}}mph (about 48{{nbsp}}km/h) to 50{{nbsp}}km/h (about 31{{nbsp}}mph)}}.
* Nominal quantities (e.g. {{xt|2{{nbsp}}×{{nbsp}}4}} ]) require consideration of whether the article is concerned with the item's actual dimensions or merely with its function. In some cases, the nominal quantity may suffice; in others it may be necessary to give the nominal size (often in non-SI units), the actual size in non-SI units, and the actual size in SI units.
* Whenever a conversion is given, the converted quantity's value should match the precision of the source {{crossref|(see {{section link||Unit conversions}})}}.
* Where the article's primary units differ from the units given in the source, the {{tlx|convert}} template's <code>|order=flip</code> flag can be used; this causes the {{em|original}} unit to be shown as secondary in the article, and the {{em|converted}} unit to be shown as primary: <code><nowiki>{{convert|200|mi|km|order=flip}}</nowiki></code> &rarr; {{xt|The two cities are {{convert|200|mi|km|order=flip}} apart.}}


===Unit conversions===
The use of the new binary prefix standards in the Misplaced Pages is not required, but is recommended for use in all articles where binary capacities are used. In articles where the precise byte capacities are important to description, the binary prefix should be used with binary capacities and the SI prefix should be used with decimal capacities (and should be noted as decimal if not immediately clear). If a contributor changes an article's usage from kilo- etc. to kibi- etc. where the units are in fact binary, that change should be accepted. However, because they are less familiar, binary unit prefixes such as ] should be linked at least once per article to avoid confusion. Link as <nowiki>]</nowiki> to avoid a disambiguation page.


{{see also|#Currency conversions|Misplaced Pages:WikiProject Astronomy/Manual of Style#Units}}
Do '''not''' change all SI prefixes to IEC prefixes in computing contexts, only those that are actually being used in a binary sense. If you don't understand the difference, don't change anything. For example, do not change a "160&nbsp;GB HDD" to "158.69&nbsp;]" (still less "160 ]"), but you can change 512&nbsp;MB RAM to 512&nbsp;] RAM where it is important to do so. ''(Notice that the number does not change because the SI prefix was used in a binary sense. Both usages are acceptable, but the MiB reference is not ambiguous.)''
{{shortcut|MOS:CONVERSIONS|MOS:CVT}}


Where English-speaking countries use different units for the same quantity, provide a conversion in parentheses: {{xt|the Mississippi River is {{convert|2320|mi|km|0}} long}}; {{xt|the Murray River is {{convert|2508|km|mi|0}} long}}. But in science-related articles, supplying such conversion is not required unless there is some special reason to do so.
Do '''not''' change SI prefixes to IEC prefixes within directly quoted passages, but it's acceptable to link to the appropriate unit.
* Where an ] is not part of the ], or vice versa{{snd}}and in particular, where those systems give a single term different definitions{{snd}}a double conversion may be appropriate: {{xt|Rosie weighed {{convert|80|kg|lb stlb}}}} (markup: <code><nowiki>{{convert|80|kg|lb stlb}}</nowiki></code>); {{xt|{{nobr|The car}} had a fuel economy of {{convert|5|L/100km|mpgus mpgimp|abbr=on}}}} (markup: <code><nowiki>{{convert|5|L/100km|mpgus mpgimp|abbr=on}}</nowiki></code>).
* Generally, conversions to and from metric units and US or imperial units should be provided, except:
** When inserting a conversion would make a common or linked expression awkward ({{xt|The four-minute mile}}).
** In some topic areas (for example, maritime subjects where nautical miles are the primary units, American football where ] are primary, and articles like ] where many interplanetary distances are given) it can be excessive to provide a conversion for every quantity. In such cases consider noting that the article will use a particular unit{{snd}}possibly giving the conversion factor to other, familiar units in a parenthetical note or a footnote{{snd}}and link the first occurrence of each unit but not give a conversion every time it occurs. Applying this principle may require editorial discretion; for example, in scientific articles the expected level of reader sophistication should be taken into account. <!-- At http://en.wikipedia.org/Wikipedia_talk:Manual_of_Style/Dates_and_numbers/Archive_155#Unit_conversions_in_science_articles there's a very long and detailed discussion about this point which kind of pooped out and might be worth reviving-->
** For distances on the scale of between ]s and ], "]s" or "ly" should be used as primary units, with a conversion to "parsecs" or "pc", but no conversion to SI units. The units should be linked on first mention. For larger quantities, use ] in prose (million or billion but not thousand) and metric prefixes (kly, Mly, Gly, kpc, Mpc, Gpc) in compact contexts. Examples:<!-- -->
*** First mention in prose: {{convert|34.6|±|2.3|e6ly|Mpc|sigfig=3|lk=on}}
**** Wikitext: <nowiki>{{convert|34.6|±|2.3|e6ly|Mpc|sigfig=3|lk=on}}</nowiki>
*** Infobox or table: {{cvt|765|kpc|Mly|order=flip|sigfig=3|lk=on}}
**** Wikitext: <nowiki>{{cvt|765|kpc|Mly|order=flip|sigfig=3|lk=on}}</nowiki> (use "order=flip" when source uses parsecs)
** ]s (au) should be converted to kilometers (km) using "million", "billion", or "trillion" in both prose and compact environments like infoboxes and tables. When large interplanetary-scale distances overlap with small interstellar-scale distances, convert au to ly and pc, or ly to pc and au (depending on context). Examples: <!-- ] -->
*** {{convert|49.3|au|e9km|abbr=unit}}
**** Wikitext: <nowiki>{{convert|49.3|au|e9km|abbr=unit}}</nowiki>
*** {{convert|121000|au|ly pc|abbr=off|lk=on}}
**** Wikitext: <nowiki>{{convert|121000|au|ly pc|abbr=off|lk=on}}</nowiki>
*** {{convert|0.9|ly|pc au|abbr=unit}}
**** Wikitext: <nowiki>{{convert|0.9|ly|pc au|abbr=unit}}</nowiki>


* For units of measure that are obsolete, obscure outside of a particular specialty or geography (e.g. ], ], or ]), or not part of the SI/] or US customary systems (e.g. zolotnik), supply a parenthetical conversion into at least SI or SI-accepted units (unless one of the exceptions previously noted applies). Convert each mention, unless this would be excessive given the context. Take care to distinguish between different definitions of the same unit if it has changed over time or differs geographically (e.g. ], ]). An approximate or range conversion is acceptable if the exact historical value is uncertain (e.g. ]).
Measures that typically use decimal multiples:
** Metric units not part of the SI or accepted for use with it should either be replaced with SI or SI-accepted units (e.g. joules instead of ]s), or they should be treated as obscure units in the same way as furlongs.
* Capacities of ] drives and some other ]
* ]es used should be commonly known, namely "pico" thru "tera", preferably in commonly-used combinations (e.g. 2,000 kilometers not 2 megameters).
* ] and ] speeds
* Converted quantity values should use a {{em|level of precision}} similar to that of the source quantity value, so {{xt|the Moon is 380,000{{nbsp}}kilometres (240,000{{nbsp}}mi) from Earth}}, not {{!xt|(236,121{{nbsp}}mi)}}. Small numbers, especially if approximate, may need to be converted to a range where rounding would cause a significant distortion, so {{xt|about one mile (1–2{{nbsp}}km)}}, not {{!xt|about one mile (2{{nbsp}}km)}}. Be careful especially when your source has already converted from the units you're now converting back to. This may be evidenced by multiples of common conversion factors in the data, such as 160 km (from 100 miles). {{crossref|See ].}}
* {{tlx|convert}} and other ] can be used to convert and format many common units, and have options to respect significant figures. To avoid problems with rounding and significant figures, for input to conversion templates use only the original quantity found in reliable sources, not one that a source has already converted. If required by the above rules, the conversion output can be displayed as the primary units with "order=flip". Conversion output can be displayed as the only units with "disp=out"; this retains the original quantity in wikitext for verification by editors.
* In a '''direct quotation''', always retain the source units. Any conversions can be supplied either in the quote itself (in square brackets, following the original measurement) or in a footnote. {{crossref|See ] and ].}}
* {{tlx|Units attention}} may be added to articles needing general attention regarding choice of units and unit conversions.


===Unit names and symbols===
Measures that typically use binary multiples:
{{redirect|WP:DEGREE|the essay on notability|WP:POSITION}}
* ] and ] sizes
{{shortcut|MOS:UNITNAMES|MOS:UNITSYMBOLS}}
* Some ]
:{{em|Definitions:}}
:* Examples of '''unit names''': foot, metre, kilometre, (''US:'' meter, kilometer).
:* Examples of '''unit symbols''': ft, m, km.
* Unit names and symbols should follow the practice of reliable sources.
* In prose, unit names should be given in full if used only a few times, but symbols may be used when a unit (especially one with a long name) is used repeatedly, after spelling out the first use (e.g. {{xt|Up to 15 kilograms of filler is used for a batch of 250{{nbsp}}kg}}).
** Exception: Certain units<!--<<perhaps identify these in table of specific units elsewhere on this page--> are generally represented by their symbols (e.g. {{xt|&deg;C}} rather than {{!xt|degrees Celsius}}) even on first use, though their unit names may be used for emphasis or clarity ({{xt|conversion of degrees Celsius to degrees Fahrenheit}}).
** Exception: Consider using ''inches'' (but not ''in.'') in place of ''in'' where the latter might be misread as a preposition<!--can someone supply an example? (if no one can think of one after a while, then maybe this exception never actually arises)-->{{mdashb}}but not where the value is followed by a parenthesized conversion e.g. {{xt|bolts 5{{nbsp}}in (12.7{{nbsp}}cm) long}}, or is part of such a conversion ({{xt|bolts 12.7{{nbsp}}cm (5{{nbsp}}in) long}}).
* Where space is limited, such as in tables, infoboxes, parenthetical notes, and mathematical formulas, unit symbols are preferred.
* Units unfamiliar to general readers should be presented as a name{{ndash}}symbol pair on first use, linking the unit name ({{xt|Energies rose from 2.3 ]s (MeV) to 6{{nbsp}}MeV}}).
** Commonly-known SI and SI-accepted units that can be used without linking are: meter (m), gram (g), second (s), ampere (A), liter (L), pascal (Pa), hertz (Hz), degrees Celsius (°C), minute (min), hour (h), day (d), degree (of angle, °), volt (V), watt (W)
* Ranges use unspaced en dash ({{tlx|ndash}}) if only one unit symbol is used at the end (e.g. {{xt|5.9{{ndash}}6.3{{nbsp}}kg}}), and spaced en dash ({{tlx|snd}}) if two symbols are used (e.g. {{xt|3{{nbsp}}μm{{snd}}1{{nbsp}}mm}}); ranges in prose may be specified using either unit symbol or unit names, and units may be stated either after both numerical values or after the last (all acceptable: {{nobr|{{xt|from 5.9 to 6.3 kilograms}}}}; {{nobr|{{xt|from 5.9 kilograms to 6.3 kilograms}}}}; {{nobr|{{xt|from 5.9 to 6.3{{nbsp}}kg}}}}; {{nobr|{{xt|from 5.9{{nbsp}}kg to 6.3{{nbsp}}kg}}}}).
* Length{{ndash}}width, length{{ndash}}width{{ndash}}height and similar dimensions may be separated by the multiplication sign (<code>×</code> or <code>&amp;times;</code>) or the word <code>by</code>.
** The {{xtn|×}} symbol is preceded by a space (preferably non-breaking), and followed by a space (which may also be non-breaking in short constructions), and each number should be followed by a unit name or symbol:
*** {{xt|1 m × 3 m × 6 m}}, not {{nobr| {{!xt|1 × 3 × 6 m}}}}, {{!xt|(1 × 3 × 6) m}}, nor {{nobr| {{!xt|1 × 3 × 6 m<sup>3</sup>}} }}
*** {{xt|a metal plate 1 ft × 3 ft × 0.25 in}}
*** {{xt|a railroad easement 10 ft × 2.5 mi}}
** With ''{{xtn|by}}'', the unit need be given only once if it is the same for all dimensions: {{nobr| {{xt|1 by 3 by 6 metres}} }} or {{nobr| {{xt|1 by 3 by 6 m}}}}.
** The unspaced letter {{xt|x}} may be used in common terms such as {{xt|]}}.


{| class="wikitable"
See ] and the talk page there for ongoing, possibly resolved debate on which style of exponent notation to use for large numbers.
|+ {{vanchor|General guidelines on use of units}}
|-
! {{Vert header|<small>Aspect</small>}}
! Guideline<!--this column picks up whatever width is left over from other columns-->
! style="width:40px;"<!--undersized width specification means column size is set by widest word/nobreaked phrase in column contents-->| ] Acceptable
! style="width:40px;"<!--undersized width specification means column size is set by widest word/nobreaked phrase in column contents-->|] Unacceptable
|-
|rowspan=8 {{Vert header|va=middle|<small>'''Unit names and symbols'''</small>}}
|Except as listed in the {{section link||Specific units}} table below, unit {{em|symbols}} are uncapi{{shy}}tal{{shy}}ized unless they are derived from a proper name, in which case the first letter (of the base unit symbol, not of any prefix) is capitalized.{{efn|1=These definitions are consistent with all units of measure mentioned in the ''SI Brochure''<ref name="SI Brochure" /> and with all units of measure catalogued in ].<ref>{{cite web |title=Council Directive of 20 December 1979 on the approximation of the laws of the Member States relating to units of measurement |id=80/181/EEC (Document 01980L0181-20090527) |work=Eur-Lex.Europa.eu |publisher=] |date=2017 |orig-year=1979 |url=http://eur-lex.europa.eu/legal-content/EN/TXT/?qid=1397640809938&uri=CELEX:01980L0181-20090527 |access-date=December 12, 2017}}</ref>}}
| {{ xt|8 kg}}<br>{{ xt|100 kPa}}
| {{!xt|8 Kg}}<br>{{!xt|100 kpa}}
|-
|Unit symbols are undotted.
|{{ xt|38 cm of rope }}
|{{!xt|38 cm<big>.</big> of rope}}
|-
|rowspan=2 | Unit {{em|names}} are given in lower case except: where any word would be capital{{shy}}ized, or where otherwise specified in the SI brochure<ref name="SI Brochure">{{cite book |title=SI Brochure: The International System of Units (SI) |edition=9th |year=2019 |publisher=] |url=https://www.bipm.org/utils/common/pdf/si-brochure/SI-Brochure-9-EN.pdf |section=Chapter 4: Non-SI units that are accepted for use with the SI |access-date=2020-09-24}} Table 8, p 145, gives additional guidance on non-SI units.</ref> or this Manual of Style.
|{{plainlist|
* {{ xt|A gallon is 4{{nbsp}}quarts.}}
* {{ xt|4 pascals}}
}}
|{{plainlist|
* {{!xt|A Gallon is 4{{nbsp}}Quarts.}}
* {{!xt|4 Pascals}}
}}
|-
|{{plainlist|
* {{ xt|He walked several miles.}}
* {{ xt|Miles of trenches were dug.}}
}}
|
|-
|The spelling of certain unit names (some of which are listed in {{section link||Specific units}}, below) varies with the ].
|
|
|-
|rowspan=2 | Write unit names and symbols in upright (]) type, except where emphasizing in context.
| {{ xt|10{{nbsp}}m}}<br>{{ xt|29 kilograms}}
| {{!xt|10{{nbsp}}{{em|m}}}}<br>{{!xt|29 {{em|kilograms}}}}
|-
| {{ xt|Thus each two-liter jug contained only two {{em|quarts}}.}}
|
|-
|Do not use precomposed unit symbol characters.
|
|{{!xt|㎓, ㎦, ㎍, ㎖, ㎉}}
|-
|rowspan=7 {{Vert header|va=middle|<small>'''Numeric values'''</small>}}<!--WARNING! ADJUST ROWSPAN WHEN ADDING/REMOVING ROWS FROM A GROUP OF RULES-->
|Do not spell out numbers before unit {{em|symbols}}{{nbsp}}...
|{{ xt|12{{nbsp}}min}}
|{{!xt|twelve{{nbsp}}min}}
|-
|...{{nbsp}}but words {{em|or}} figures may be used with unit {{em|names}}.
|{{plainlist|
* {{ xt|twelve minutes}}
* {{ xt|12 minutes}}
}}
|
|-
| Use a non-breaking space ({{tlx|nbsp}} or <code>&amp;nbsp;</code>) between a number and a unit {{em|symbol}}, or use {{tlx|nowrap}}{{nbsp}}...
| {{xt|29{{nbsp}}kg}} {{nowr|(markup: <code>29&amp;nbsp;kg</code>}} or {{nowr|<code><nowiki>{{nowrap|29 kg}}</nowiki></code>)}}
| style="vertical-align: top"| {{!xt|29kg}}
|-
| ... though with certain symbols ''no'' space is used (see "Specific{{nbsp}}units" table below){{nbsp}}...
| {{nobr|{{xt|23&deg;}} {{xt|47&prime;}} {{xt|22&Prime;}} }}
| {{nobr|{{!xt|23{{nbsp}}&deg;}} {{!xt|47{{nbsp}}&prime;}} {{!xt|22{{nbsp}}&Prime;}} }}
|-
| ... and a normal space is used between a number and a unit {{em|name}}.
| {{xt|29{{nbsp}}kilograms}}<br>(markup: <code>29{{nbsp}}kilograms</code>)
|
|-
|To form a value and a unit {{em|name}} into a compound adjective use a hyphen or hyphens{{nbsp}}...
|{{plainlist|
* {{ xt|a five-day holiday}}
* {{ xt|a five-cubic-foot box}}
* {{ xt|a 10-centimeter blade}}
}}
|
|-
|... but a non-breaking space (never hyphen) separates a value and unit {{em|symbol}}.
|{{plainlist|
* {{ xt|a blade 10 cm long}}<!--What about "a 10 cm bridge"?-->
}}
| {{!xt|a 10-cm blade}}
|-
|rowspan=5 {{Vert header|va=middle|<small>'''Plurals'''</small>}}<!--WARNING! ADJUST ROWSPAN WHEN ADDING/REMOVING ROWS FROM A GROUP OF RULES-->
|] unit {{em|names}} are pluralized by adding {{xt|-s}} or {{xt|-es}}{{nbsp}}...<!--Not that it matters much, but I'm having trouble finding an SI unit taking -es. -->
|{{ xt|1 ohm}}; {{xt|10 ohms}}<!--What's an example with "-es"?-->
|
|-
| ... except for these irregular forms.
| {{ xt|1 henry}}; {{ xt|10 henries}}<br>{{ xt|1 hertz}}; {{ xt|10 hertz}}<br>{{ xt|1 lux}}; {{xt|10 lux}}<br>{{ xt|1 siemens}}; {{xt|10 siemens}}
|{{!xt|10 henrys }}<br>{{!xt|10 hertzes}}<br>{{!xt|10 luxes}}<br>{{!xt|10 siemenses}}
|-
|rowspan=2 | Some non-SI units have irregular plurals.<!--This is meant to be placeholder which perhaps someone can expand (though foot, feet is the only example I can think of at the moment).--><!--Pedal, peddle (more, meet; group, greet; trump, tweet) ... mouth, momentous ... are we there yet ...-->
| {{ xt|1 foot}}; {{xt|10 feet}}
| {{!xt|10 foots}}
|-
| {{ xt|1 stratum}}; {{nobr|{{xt|10 strata}} (unusual)}} <!--Rare, but is occasionally used as a measurement unit; can't think of any others, didn't find any in searching.-->
| {{!xt|10 stratums}}
|-
|Unit {{em|symbols}} (in any system) are identical in singular and plural.
|{{plainlist|
* {{nobr|{{xt|grew from 1 in to 2 in}} }}
* {{nobr|{{xt|grew from 1 inch to 2 inches}} }}
* {{nobr|{{xt|grew from one to two inches}} }}
}}
|{{nobr|{{!xt|grew from 1 in to 2 ins}} }}
|-
|rowspan=5 {{Vert header|va=middle|<small>'''Powers'''</small>}}<!--WARNING! ADJUST ROWSPAN WHEN ADDING/REMOVING ROWS FROM A GROUP OF RULES-->
|Format exponents using <nowiki><sup></nowiki>, not special characters.
|{{xt|km<sup>2</sup>}}<br>{{nobr|(markup: <code>km&lt;sup>2&lt;/sup></code>)}}
|{{!xt|km&#178;}}<br>(<code>km&amp;#178;</code>)
|-
|Or use {{xtn|squared}} or {{xtn|cubed}} ({{em|after}} the unit being modified).
|rowspan=2|{{xt|ten metres per second squared}}
|{{!xt|ten metres per squared second}}
|-
|rowspan=2| For areas or volumes only, {{xtn|square}} or {{xtn|cubic}} may be used ({{em|before}} the unit being modified).
|{{!xt|ten metres per square second}}
|-
|{{xt|tons per square mile}}
|
|-
| {{xtn|sq}} or {{xtn|cu}} may be used with US customary or imperial units, but not with ] units.
| {{ xt|15{{nbsp}}sq{{nbsp}}mi}}<br>{{ xt|3{{nbsp}}cu{{nbsp}}ft }}
| {{!xt|15{{nbsp}}sq{{nbsp}}km}}<br>{{!xt|3{{nbsp}}cu{{nbsp}}m }}
|-
|rowspan=4 {{Vert header|va=middle|<small>'''Products'''</small>}}<!--WARNING! ADJUST ROWSPAN WHEN ADDING/REMOVING ROWS FROM A GROUP OF RULES-->
|Indicate a product of unit {{em|names}} with either a hyphen or a space.
|{{plainlist|
* {{ xt|foot-pound}}
* {{ xt|foot pound}}
}}
|{{plainlist|
* {{!xt|footpound}}
* {{!xt|foot&sdot;pound}}
}}
|-
|Indicate a product of unit {{em|symbols}} with <code>&amp;];</code> or <code>&amp;];</code>.
|{{plainlist|1= <!-- 1= is needed because text below contains = -->
* {{ xt|ms}} = millisecond
* {{ xt|m&sdot;s}} or {{xt|m{{nbsp}}s}} = metre-second
}}
|
|-
|{{em|Exception:}} In some topic areas, such as power engineer{{shy}}ing, certain products take neither space nor <code>&amp;sdot;</code>. Follow the practice of reliable sources in the article's topic area.
|{{plainlist|
* ], ], ]
* {{xt|kWh}}, {{xt|MVA}}, {{xt|GAh}}
}}
|
|-
|To pluralize a product of unit {{em|names}}, pluralize only the final unit. (Unit {{em|symbols}} are never pluralized.)
|{{ xt|ten foot-pounds}}
|{{!xt|ten feet-pounds}}
|-
|rowspan=7 {{Vert header|va=middle|<small>'''Ratios, rates, densities'''</small>}}<!--WARNING! ADJUST ROWSPAN WHEN ADDING/REMOVING ROWS FROM A GROUP OF RULES-->
|Indicate a ratio of unit {{em|names}} with {{xtn|per}}.
|{{ xt|meter per second}}
|{{!xt|meter/second}}
|-
|rowspan=2|Indicate a ratio of unit {{em|symbols}} with a forward slash (<code>/</code>), followed by either a single symbol or a parenthesized product of symbols{{snd}}do not use multiple slashes. Or use{{nbsp}}<sup>&minus;1</sup>,{{nbsp}}<sup>&minus;2</sup>, etc.
|{{plainlist|
* {{ xt|metre per second}}
* {{ xt|m/s}}
* {{ xt|m&sdot;s<sup>&minus;1</sup>}}
}}
|{{plainlist|
* {{!xt|mps}}
}}
|-
|{{plainlist|
* {{ xt|kg/(m&sdot;s)}}
* {{ xt|kg&sdot;m<sup>&minus;1</sup>&sdot;s<sup>&minus;1</sup>}}
}}
|{{plainlist|
* {{!xt|kg/m&sdot;s}}
* {{!xt|kg/m/s}}
}}
|-
|To pluralize a ratio of unit {{em|names}}, pluralize only the numerator unit. (Unit {{em|symbols}} are never pluralized.)
|{{plainlist|
* {{nowrap|{{xt|ten newton-metres per second}} }}<!--Nowrap on longest value in column establishes minimum col width.-->
* {{xt|10 N&sdot;m/s}}
}}
|
|-
|Some of the special forms used in the imperial and US customary systems are shown here{{nbsp}}...
|{{plainlist|1= <!--1= is needed because text below contains =-->
* {{ xt|mph}} = miles per hour
* {{ xt|mpg}} = miles per gallon
* {{ xt|psi}} = ] per square inch
}}
|
|-
|rowspan=2| ... but only the slash or negative exponent notations are used with SI (and other metric) units.
| {{plainlist|
* {{ xt|g/m<sup>2</sup>}}
* {{ xt|g&sdot;m<sup>&minus;2</sup>}}
}}
| {{!xt|gsm}}
|-
| {{plainlist|
* {{ xt|km/h}}
* {{ xt|km&sdot;h<sup>&minus;1</sup>}}
}}
| {{!xt|kph}}
|-
|rowspan=4 {{Vert header|va=middle|<small>'''Prefixes'''</small>}}<!--WARNING! ADJUST ROWSPAN WHEN ADDING/REMOVING ROWS FROM A GROUP OF RULES-->
|Prefixes should not be separated by a space or hyphen.
|{{ xt|kilopascal}}
|{{plainlist|
* {{!xt|kilo pascal}}
* {{!xt|kilo-pascal}}
}}
|-
| Prefixes are added without contraction,<!--give example--> except as shown here:
| {{ xt|kilohm }}<br>{{ xt|megohm }}<br>{{xt|hectare}}
| {{!xt|kiloohm}}<br>{{!xt|megaohm}}<br>{{!xt|hectoare}}
|-
|The {{xtn|deci-}}, {{xtn|deca-}}, and {{xtn|hecto-}} prefixes should generally be avoided; exceptions include<!--Check SI source; also, since we're supposed to follow the units in sources, don't those control anyway?--> decibel, hectolitre, hectare, and hectopascal.
|{{plainlist|
* {{ xt|100 metres}}
* {{ xt|0.1 km}}
}}
|{{!xt|1 hectometre}}
|-
| Do not use ] for 10<sup>3</sup>, {{!xt|MM}} for 10<sup>6</sup>, or {{!xt|B}} for 10<sup>9</sup> (except as noted elsewhere on this page for {{xtn|M}} and {{xtn|B}}, e.g. ])
| {{ xt|3 km }}<br>{{ xt|8 MW }}<br>{{ xt|125 GeV}}
| {{!xt|3 Mm }}<br>{{!xt|8 MMW }}<br>{{!xt|125 BeV}}
|-
|rowspan=4 {{Vert header|va=middle|<small>'''Mixed units'''</small>}}<!--← Use <br> to make this column as narrow as possible.--><!--WARNING! ADJUST ROWSPAN WHEN ADDING/REMOVING ROWS FROM A GROUP OF RULES-->
|rowspan=2| Mixed units are traditionally used with the imperial and US customary systems{{nbsp}}...
|{{anchor|Mixed units}}<!--← This anchor should go at the portion of the row which is vertically highest.-->{{plainlist|
* {{xt|a wall 1 ft 1 in thick}}
* {{xt|a wall 1 foot 1 inch thick }}
* {{xt|a man 6 feet 2 inches tall}}
* {{xt|a 6-foot 2-inch man}}
* {{xt|a 6 ft 2 in man}}
}}
|{{plainlist|
* {{nobr| {{!xt|1 ft{{hsp}}, 1 in }} (no comma) }}
* {{!xt|1 foot{{hsp}}, 1 inch}}
* {{!xt|a man 6 foot 2 tall}}
* {{!xt|a 6-foot 2 man}}
* {{nbsp}}
}}
|-
|{{plainlist|
* {{xt|1 US fl pt 8 oz}}
* {{xt|1 US fl pt 8 US fl oz}}
}}
|
|-
|... and in expressing time durations{{nbsp}}...
|{{plainlist|
* {{xt|1:30:07}}
* {{xt|1:30}}{{thinsp}}<ref group="note">Use this format only where it is clear from context whether it means hours and minutes (HH:MM) or minutes and seconds (MM:SS).</ref>
* {{xt|{{nobr|1 h 30 min 7 s}}}}
* {{xt|{{nobr|01<sup>h</sup> 30<sup>m</sup> 07<sup>s</sup>}}}}{{thinsp}}{{refn|group=note|This format is used in astronomy (see the IAU Style Manual<ref>{{cite book |title=IAU Style Manual |first=G. A. |last=Wilkins |chapter=5.14 Time and angle |page=S23 |date=1989 |url= https://www.iau.org/static/publications/stylemanual1989.pdf |format=PDF |publisher=] |access-date=12 December 2017}}</ref> for details).}}
}}
||{{plainlist|
* {{!xt|{{nobr|1:30&prime;07&Prime;}}}}
* {{!xt|{{nobr|1:30&prime;}}}}
* {{!xt|{{nobr|1 hr 30 min 7 sec}}}}
* {{!xt|{{nobr|1 h 30 m 7 s}}}}
}}
|-
|... but are not used with metric units.
|{{plainlist|
* {{xt|1.33 m }}
* {{xt|133 cm }}
}}
|{{!xt|1 m 33 cm}}
|}
{{em|Note to table:}}
{{reflist | group=note}}


===Specific units===
==Geographical coordinates==
] on ] should be entered using a template. This standardizes the format. It also provides a link to a page with several links to maps of the coordinates, and is part of a new way to handle geographic information in Misplaced Pages.


{{shortcut|MOS:FOOT|MOS:INCH}}
Depending on the form of the coordinates, three template formats are available. For just degrees, use '''d''' mode:
* The following table lists only units that need special attention.
: <code><nowiki>{{</nowiki>coor d|''DD''|''N/S''|''DD''|''E/W''|}}</code>
* The ''SI Brochure''<ref name="SI Brochure" /> should be consulted for guidance on use of other SI and non-SI units.
For degrees/minutes, use '''dm''' mode:
: <code><nowiki>{{</nowiki>coor dm|''DD''|''MM''|''N/S''|''DD''|''MM''|''E/W''|}}</code>
For degrees/minutes/seconds, use '''dms''' mode:
: <code><nowiki>{{</nowiki>coor dms|''DD''|''MM''|''SS''|''N/S''|''DD''|''MM''|''SS''|''E/W''|}}</code>


{|class="wikitable"
Where:
|+ Guidelines on specific units
* ''DD'', ''MM'', ''SS'' are the degrees, minutes, seconds listed one by one
|-
* ''N/S'' is either '''N''' or '''S''', depending on which hemisphere
! {{Vert header|<small>Group</small>}}
* ''E/W'' is either '''E''' or '''W''', depending on which hemisphere
! style="width:40px;"<!--undersized width specification means column size is set by widest word/nobreaked phrase in column contents-->| Unit name
! style="width:40px;"<!--undersized width specification means column size is set by widest word/nobreaked phrase in column contents-->| Unit symbol
! Comment<!--this column picks up whatever width is left over from other columns-->
|-
| rowspan = 8 {{Vert header|va=middle|<small>'''Length, speed'''</small>}}<!--WARNING! ADJUST ROWSPAN WHEN ADDING/REMOVING ROWS FROM A GROUP OF UNITS-->
| {{plainlist|
* inch
* foot
}}
| {{plainlist|
* {{ xt|in}}
* {{ xt|ft}}
}}
| Do not use <code>&amp;prime;</code>{{nbsp}}({{!xt|&prime;}}), <code>&amp;Prime;</code>{{nbsp}}({{!xt|{{pprime}}}}), apostrophe{{nbsp}}({{!xt|'}}), or quote{{nbsp}}({{!xt|"}}). Exception: in music, ] notation describes organ stops and wind instrument lengths in feet. A prime may be used with an explanation on first use, e.g. {{tq|a ] (16′) organ pedal stop}}; see ].
|-
| foot per second
| {{xt|ft/s}} ({{em|not}} {{!xt|]}})
|
|-
| ]
| {{xt|h}} or {{xt|hh}}
| Equal to 4 inches; used in measurement of horses. A dot may be followed by additional inches e.g. {{nobr|{{xt|16.2 hh}}}} indicates {{nobr|16 hands 2 inches.}}
|-
|{{plainlist|
* ]
* {{nobr|knot ]}}
* {{nobr|knot ]}}
* {{nobr|knot ]}}
* {{nobr|knot ]}}
* {{nobr|knot ]}}
}}
|{{plainlist|
* {{nobr|{{xt|kn}} {{nobr|({{em|not}} {{!xt|]}}, {{!xt|]}}, or {{!xt|]}})}}}}
* {{nobr|{{xt|KIAS}} or {{xt|kn}}}}
* {{xt|KCAS}}
* {{xt|KEAS}}
* {{xt|KTAS}}
* {{nobr|{{xt|kn}} {{nobr|({{em|not}} {{!xt|KGS}})}}}}
}}
| Used in aviation contexts for aircraft and wind speeds, and also used in some nautical and general meteorological contexts. When applied to aircraft speeds, {{xt|kn}} means {{xt|KIAS}} unless stated otherwise; if {{xt|kn}} is used for calibrated airspeed, equivalent airspeed, true airspeed, or groundspeed, explicitly state and link to, upon first use, the type of speed being referred to (for instance, {{xt|kn ]}}, or, if severely short of space, {{xt|kn ]}}); for airspeeds other than indicated airspeed, the use of the specific abbreviation for the type of airspeed being referred to (such as {{xt|KEAS}}) is preferred. When referring to indicated airspeed, either {{xt|kn}} or {{xt|KIAS}} is permissible. Groundspeeds and wind speeds ''must'' use the abbreviation {{xt|kn}} only.
|-
| {{plainlist|
* metre
* meter {{em|(US)}}
}}
| {{xt|m}}
|
|-
| micron
| {{xt|&mu;m}} ({{em|not}} {{!xt|&mu;}})
| Markup: <code>&amp;mu;m</code>{{nbsp}} Link to ] (for which micron is a synonym) on first use.
|-
| ]
| {{xt|au}}<br>{{nobr| ({{em|not}} {{!xt|A.U.}}, {{!xt|ua}}) }}
| The preferred form is {{xt|au}}. Articles that already use {{xtn|AU}} may switch to au or continue with AU; seek consensus on the talk page.
|-
|{{plainlist|
* mile
* miles per hour
* nautical mile
}}
|{{plainlist|
* {{xt|mi}}
* {{xt|mph}}<!--not ever mi/h??-->
* {{nobr| {{xt|nmi}} or {{xt|NM}} {{nobr|({{em|not}} {{!xt|]}} or {{!xt|M}})}} }}
}}
| In nautical and aeronautical contexts where there is risk of confusion with nautical miles, consider writing out references to ]s as e.g. {{xt|5{{nbsp}}statute{{nbsp}}miles}} rather than simply {{!xt|5{{nbsp}}miles}}.
|-
| rowspan = 7 {{Vert header|va=middle|<small>'''Volume, flow'''</small>}}<!--WARNING! ADJUST ROWSPAN WHEN ADDING/REMOVING ROWS FROM A GROUP OF UNITS-->
| rowspan = 2 | {{plainlist|
* cubic centimetre
* {{nobr| cubic centimeter {{em|(US)}} }}
}}
| {{xt|cm<sup>3</sup>}}
| Markup: <code><nowiki>cm<sup>3</sup></nowiki></code>
|-
| {{xt|cc}}
| Non-SI abbreviation used for certain ]s. Link to ] on first use.<!--I wonder if this can't be better coordinated with mpg, mph, etc. in earlier table.-->
|-
|{{plainlist|
* imperial fluid ounce
* imperial pint
* imperial quart
* imperial gallon
* US fluid ounce
* US dry pint
* US liquid pint
* US dry quart
* US liquid quart
* US gallon
}}
|{{plainlist|
* {{xt|imp fl oz}}
* {{xt|imp pt}}
* {{xt|imp qt}}
* {{xt|imp gal}}
* {{xt|US fl oz}}
* {{xt|US dry pt}}
* {{xt|US liq pt}}
* {{xt|US dry qt}}
* {{xt|US liq qt}}
* {{xt|US gal}}
}}
|
*{{xtn|US}} or {{xtn|imperial}} (or {{xtn|imp}}) must be specified for all these units.
*{{xtn|fluid}} or {{xtn|fl}} must be specified for fluid ounces (to avoid ambiguity versus ] and ]).
*For US pints and quarts, {{xtn|dry}} or {{xtn|liquid}} ({{xtn|liq}}) are needed to be fully unambiguous, though context determines whether or not to repeat those qualifiers on every use in a given article.
|-
| cubic foot
| {{xt|cu ft}} ({{em|not}} {{!xt|cf}})
| Write {{xt|five million cubic feet}}, {{xt|5,000,000{{nbsp}}cu{{nbsp}}ft}}, or {{xt|{{val|5|e=6|u=cuft}}}}, not {{!xt|5{{nbsp}}MCF}}.
|-
| {{nobr| cubic foot per second }}
| {{xt|cu ft/s}} ({{em|not}} {{!xt|cfs}})
|
|-
| {{plainlist|
* litre
* liter {{em|(US)}}
}}
| {{nobr|{{xt|L}} {{nobr|({{em|not}} {{!xt|l}} or {{!xt|ℓ}})}}}}
| The symbol l (lowercase "el") in isolation (i.e. outside forms as ml) is easily mistaken for the digit{{nbsp}}1 or the capital {{nobr|letter I ("eye")}} and should not be used.
|-
| {{plainlist|
* millilitre
* milliliter {{em|(US)}}
}}
| {{xt|ml}} or {{xt|mL}}
| Derivative units of the litre may use l (lowercase "el").
|-
| rowspan=7 {{Vert header|va=middle|<small>'''Mass, weight, force, density, pressure'''</small>}}<!--WARNING! ADJUST ROWSPAN WHEN ADDING/REMOVING ROWS FROM A GROUP OF UNITS-->
|{{plainlist|
* gram
* kilogram
}}
|{{plainlist|
* {{xt|g}}
* {{xt|kg}}
}}
| Not {{!xt|gramme}}, {{!xt|kilogramme}}
|-
|{{plainlist|
* ]
* ]
}}
|{{plainlist|
* {{xt|long ton}}
* {{xt|short ton}}
}}
| Spell out in full.
|-
| {{plainlist|
* ]
* ] {{em|(US)}}
}}
| {{xt|t}} {{nobr|({{em|not}} {{!xt|mt}}, {{!xt|MT}}, or {{!xt|]}})}}
|
|-
| {{nobr| pound per square inch }}
| {{xt|psi}}
|
|-
|{{plainlist|
*troy ounce
*troy pound
}}
|{{plainlist|
*{{xt|oz t}}
*{{xt|lb t}}
}}
|rowspan=2| The qualifier {{xtn|t}} or {{xtn|troy}} must be specified where applicable. Use the qualifier avdp (]) only where there is risk of confusion with troy ounce, imperial fluid ounce, US fluid ounce, or troy pound; but articles about precious metals, black powder, and gemstones<!--Is this list complete?--> should always specify which type of ounce (avoirdupois or ]) is being used, noting that these materials are normally measured in troy ounces and grams.
|-
|{{plainlist|
*avoirdupois ounce
*avoirdupois pound
}}
|{{plainlist|
*{{xt|oz}} or {{xt|oz avdp}}
*{{xt|lb}} or {{xt|lb avdp}}
}}
|-
| ]
| {{xt|carat}}
| Used to express masses of gemstones and pearls.
|-
| {{Vert header|va=middle|<small>'''Purity'''</small>}}<!--WARNING! ADJUST ROWSPAN WHEN ADDING/REMOVING ROWS FROM A GROUP OF UNITS-->
| ]
| {{nobr|{{xt|k}} or {{xt|Kt}} {{nobr|({{em|not}} {{!xt|]}} or {{!xt|]}})}}}}
| A measure of purity for gold alloys. (Do not confuse with the unit of mass with the same spelling.)
|-
| rowspan=3 {{Vert header|va=middle|<small>'''Time'''</small>}}
| {{plainlist|
* second
* minute
* hour
}}
| {{plainlist|
* {{xt|s}}
* {{xt|min}}
* {{xt|h}}
}}
|Do not use <code>&amp;prime;</code>{{nbsp}}({{!xt|&prime;}}), <code>&amp;Prime;</code>{{nbsp}}({{!xt|&Prime;}}), apostrophe{{nbsp}}({{!xt|'}}) or quote{{nbsp}}({{!xt|"}}) for minutes or seconds. See also the hours–minutes–seconds formats for time durations described in the ].
|-
| rowspan=2|year
| {{xt|a}}
| Use {{xtn|a}} only with an ] ({{xt|a rock formation 540{{nbsp}}Ma{{nbsp}}old}}, not {{!xt|Life expectancy rose to 60{{nbsp}}a}}).
|-
| {{xt|y}} or {{xt|yr}}
| {{crossref|See {{section link||Long periods of time}} for all affected units.}}
|-
| rowspan=4 <!--WARNING! ADJUST ROWSPAN WHEN ADDING/REMOVING ROWS FROM A GROUP OF UNITS-->{{Vert header|va=middle|<small>'''Information, data'''</small>}}
| bit
| {{xt|bit}} {{nobr|({{em|not}} {{!xt|b}} or {{!xt|B}})}}
| rowspan=4 | {{anchor|WP:MOSBPS}}{{crossref|See also {{section link||Quantities of bytes and bits}}, below.}} Do not confuse bit/second or byte/second with ].
|-
| byte
| {{nobr| {{xt|B}} or {{xt|byte}} ({{em|not}} {{!xt|b}} or {{!xt|]}}) }}
|-
| bit per second
| {{xt|bit/s}} ({{em|not}} {{!xt|bps}}, {{!xt|b/s}})
|-
| byte per second
| {{xt|B/s}} or {{xt|byte/s}} {{nobr|({{em|not}} {{!xt|Bps}}, {{!xt|bps}}, {{!xt|b/s}})}}
|-
| rowspan = 4 {{Vert header|va=middle|<small>'''Angle'''</small>}}<!--WARNING! ADJUST ROWSPAN WHEN ADDING/REMOVING ROWS FROM A GROUP OF UNITS-->
|-
| ]
| {{xt|{{prime}}}}
| Markup: <code>{{tl|prime}}</code>{{nbsp}} (] not apostrophe/{{zwsp}}single quote{{nbsp}}{{!xt|'}}). {{nobr|No space ({{xt|47{{prime}}}}, not {{!xt|47{{nbsp}}{{prime}}}}). }}
|-
| ]
| {{xt|{{pprime}}}}
| Markup: <code>{{tl|pprime}}</code>{{nbsp}} (] not double-quote{{nbsp}}{{!xt|"}}). {{nobr|No space ({{xt|22{{pprime}}}}, not {{!xt|22{{nbsp}}{{pprime}}}}). }}
|-
| degree
| {{xt|°}}
| Markup: degree ° not ] {{!xt|&#186;}} or ]{{nbsp}}{{thinsp}}{{!xt|&#778;}}. {{nobr|No space ({{xt|23°}}, not {{!xt|23{{nbsp}}°}}). }}
|-
| rowspan = 4 {{Vert header|va=middle|<small>'''Temperature'''</small>}}<!--WARNING! ADJUST ROWSPAN WHEN ADDING/REMOVING ROWS FROM A GROUP OF UNITS-->
| degree Fahrenheit
| {{xt|°F}} ({{em|not}} {{!xt|F}})
| rowspan = 3 | Markup: {{nobr|<code>12{{tl|nbsp}}°C</code>}}, not {{nobr|<s><code>12°C</code></s>}} or {{nobr|<s><code>12°{{t|nbsp}}C</code></s> }}. Do not use the ]s {{unichar|2103|Degree Celsius}} or {{unichar|2109|Degree Fahrenheit}}.
|-
| degree ]
| {{xt|°R}} ({{em|not}} {{!xt|R}})
|-
| degree Celsius {{nobr|({{em|not}} degree centigrade)}}
| {{xt|°C}} ({{em|not}} {{!xt|C}})
|-
| ] {{nobr|({{em|not}} degree kelvin)}}
| {{xt|K}} ({{em|not}} {{!xt|°K}})
| Use a non-breaking space: <code><nowiki>12{{nbsp}}K</nowiki></code> (use ], not {{unichar|212A|KELVIN SIGN}}). When writing out the unit (not usually necessary), pluralize, e.g. {{xt|12 kelvins}} (see ])
|-
| rowspan = 2 {{Vert header|va=middle|<small>'''Energy'''</small>}}<!--WARNING! ADJUST ROWSPAN WHEN ADDING/REMOVING ROWS FROM A GROUP OF UNITS-->
| {{plainlist|
* ]
* small calorie
* gram calorie
}}
| {{xt|cal}}
| rowspan=2 | In certain subject areas, ''calorie'' is convention{{shy}}ally used alone; articles following this practice should specify on first use whether the use refers to the small calorie or to the kilocalorie (large calorie). Providing conversions to ] units (usually calories to joules or kilocalories to kilojoules) may also be useful. A kilocalorie ({{xt|kcal}}) is 1000 calories. A calorie (small calorie) is the amount of energy required to heat 1 gram of water by 1{{nbsp}}°C. A kilocalorie is also a kilogram calorie.
|-
| {{plainlist|
* ]
* large calorie
* kilogram calorie
* ({{em|not}} Calorie{{snd}}{{nobr|can be ambiguous)}}
}}
| {{xt|kcal}}
|}


==== Quantities of bytes and bits <span id="Binary prefixes"></span> ====
===Examples===


{{shortcut|MOS:COMPUNITS}}
For the city of ], located at '''59° 55&prime; N, 10° 44&prime; E''', enter:
:<code><nowiki>{{coor dm|59|55|N|10|44|E|}}</nowiki></code>
which becomes {{coor dm|59|55|N|10|44|E|}}


In quantities of ] and ]s, the prefixes {{xtn|kilo-}} (symbol {{xtn|k}} or {{xtn|K}}), {{xtn|mega-}} ({{xtn|M}}), {{xtn|giga-}} ({{xtn|G}}), {{xtn|tera-}} ({{xtn|T}}), etc., are ambiguous in general usage. The meaning may be based on a decimal system (like the standard ] prefixes), meaning 10<sup>3</sup>, 10<sup>6</sup>, 10<sup>9</sup>, 10<sup>12</sup>, etc., or it may be based on a binary system, meaning 2<sup>10</sup>, 2<sup>20</sup>, 2<sup>30</sup>, 2<sup>40</sup>, etc. The binary meanings are more commonly used in relation to solid-state memory (such as ]), while the decimal meanings are more common for data transmission rates, disk storage and in theoretical calculations in modern academic textbooks.
{{Bit and byte prefixes}}
Follow these recommendations when using these prefixes in Misplaced Pages articles:
* Following the SI standard, a lower-case {{xt|k}} should be used for "kilo-" whenever it means 1000 in computing contexts, whereas a capital {{xt|K}} should be used instead to indicate the binary prefix for 1024 according to JEDEC. If, under the exceptions detailed further below, the article otherwise uses IEC prefixes for binary units, use {{xt|Ki}} instead.
* Do not assume that the binary or decimal meaning of prefixes will be obvious to everyone. Explicitly specify the meaning of k and K as well as the primary meaning of M, G, T, etc. in an article ({{tlx|BDprefix}} is a convenient helper). Consistency within each article is desirable, but the need for consistency may be balanced with other considerations.
* The definition most relevant to the article should be chosen as primary for that article, e.g. specify a binary definition in an article on RAM, decimal definition in an article on ], ]s, and a binary definition for Windows file sizes, despite files usually being stored on hard drives.
* Where consistency is not possible, specify wherever there is a deviation from the primary definition.
* Disambiguation should be shown in bytes or bits, with clear indication of whether in binary or decimal base. There is no preference in the way to indicate the number of bytes and bits, but the notation style should be consistent within an article. Acceptable examples include:
** {{xt|A 64{{nbsp}}MB ({{nowrap|64{{nbsp}}×{{nbsp}}1024<sup>2</sup>-byte)}} video card and a 100{{nbsp}}GB {{nowrap|(100{{nbsp}}×{{nbsp}}1000<sup>3</sup>-byte)}} hard drive}}
** {{xt|A 64{{nbsp}}MB ({{nowrap|64{{nbsp}}×{{nbsp}}2<sup>20</sup>-byte)}} video card and a 100{{nbsp}}GB {{nowrap|(100{{nbsp}}×{{nbsp}}10<sup>9</sup>-byte)}} hard drive}}
** {{xt|A 64{{nbsp}}MB {{nowrap|(67,108,864-byte)}} video card and a 100{{nbsp}}GB {{nowrap|(100,000,000,000-byte)}} hard drive}}
* Avoid combinations with inconsistent form such as {{!xt|A 64{{nbsp}}MB {{nowrap|(67,108,864-byte)}} video card and a 100{{nbsp}}GB {{nowrap|(100{{nbsp}}×{{nbsp}}1000<sup>3</sup>-byte)}} hard drive}}. Footnotes, such as those seen in , may be used for disambiguation.
* Unless explicitly stated otherwise, one byte is eight bits (see {{crossref|{{section link|Byte|History}}}}).
*{{shortcut|MOS:BINPREFIX}}The ]es {{xtn|kibi-}} (symbol {{xtn|Ki}}), {{xtn|mebi-}} ({{xtn|Mi}}), {{xtn|gibi-}} ({{xtn|Gi}}), etc., are generally not to be used except:{{efn|1=Misplaced Pages follows common practice regarding ]s and other data traditionally quantified using ]es (e.g. {{xtn|mega-}} and {{xtn|kilo-}}, meaning 2<sup>20</sup> and 2<sup>10</sup> respectively) and their unit symbols (e.g. {{xtn|MB}} and {{xtn|KB}}) for RAM and ]es for most other uses. Despite the IEC's 1998 international standard creating several new binary prefixes (e.g. mebi-, kibi-, etc.) to distinguish the meaning of the decimal ]es (e.g. {{xtn|mega-}} and {{xtn|kilo-}}, meaning 10<sup>6</sup> and 10<sup>3</sup> respectively) from the binary ones, and the subsequent incorporation of these IEC prefixes into the ], consensus on Misplaced Pages in computing-related contexts favours the retention of the more familiar but ambiguous units {{xtn|KB}}, {{xtn|MB}}, {{xtn|GB}}, {{xtn|TB}}, {{xtn|PB}}, {{xtn|EB}}, etc. over use of unambiguous IEC binary prefixes. {{crossref|For detailed discussion, see ].}} }}
** when the majority of cited sources on the article topic use IEC prefixes;
** in a direct quote using the IEC prefixes;
** when explicitly discussing the IEC prefixes; or
** in articles in which both types of prefix are used with neither clearly primary, or in which converting all quantities to one or the other type would be misleading or lose necessary precision, or declaring the actual meaning of a unit on each use would be impractical.


==Currencies and monetary values<span id="Currencies"></span>==
For a country, like ], the '''d''' mode is more appropriate:
:<code><nowiki>{{coor d|22|S|24|E|}}</nowiki></code>
which becomes {{coor d|22|S|24|E|}}


{{shortcut|MOS:$|MOS:&pound;|MOS:€|MOS:CURRENCY|MOS:MONEY}}
{{redirect-multi|2|WP:MONEY|WP:CURRENCY|the WikiProject focusing on articles about currencies|Misplaced Pages:WikiProject Numismatics}}
{{redirect2|WP:$|WP:£|the policy on paid editing|Misplaced Pages:Paid-contribution disclosure|the humor page|Help:Buying Misplaced Pages}}


'''Choice of currency'''<!-- >>>>>>>> Headings in this section formatted using bold, instead of he usual === style, as permitted by MOS:PSEUDOHEAD: "If you want to reduce the size of the table of contents (TOC), use {{TOC limit}} ... In cases where {{TOC limit}} cannot be used because of lower-level headings elsewhere in the article, then using bold for the sub-sub-sub headings causes the least annoyance for screen reader users a rarity."-->
For higher ], use the '''dms''' mode:
* In '''country-specific articles''', such as ], use the currency of the subject country.
:<code><nowiki>{{coor dms|33|56|24|N|118|24|00|W|}}</nowiki></code>
* In '''non-country-specific articles''', such as ], use US dollars ({{xt|US$123}} on first use, generally {{xt|$123}} thereafter), euros ({{xt|&euro;123}}), or pounds sterling ({{xt|&pound;123}}).
which becomes {{coor dms|33|56|24|N|118|24|00|W|}}


'''Currency names'''
* Do not capitalize the names or denominations of currencies, currency subdivisions, coins and banknotes: not {{!xt|a Five-Dollar bill, four Quarters, and one Penny total six Dollars one Cent}} but {{xt|a five-dollar bill, four quarters, and one penny total six dollars one cent}}. ''Exception:'' where otherwise required, as at the start of a sentence or in such forms as {{xt|Australian dollar}}.
* To pluralize {{xtn|euro}}, use the standard English plurals ({{xt|ten euros and fifty cents}}), not the ] ({{!xt|ten euro and fifty cent}}). For the adjectival form, use a hyphenated singular ({{xt|a two-euro pen and a ten-cent coin}}).
* Link the first occurrence of lesser-known currencies (e.g. {{xt|]s}}).<!--Should a symbol be introduced at this time?-->


'''Currency symbols'''{{anchor|Currency symbols}}<!--Symbols, signifiers, abbreviations? See ] and ]s.-->
Examples of articles using geographical coordinates:
* In general, the first mention of a particular currency should use its full, unambiguous signifier (e.g. {{xt|{{A$|52|link=yes}}}}), with subsequent references using just the appropriate symbol (e.g. {{xt|$88}}), unless this would be unclear. {{em|Exceptions:}}
* Airports: ]
** In an article referring to multiple currencies represented by the same symbol (e.g. the dollars of the US, Canada, Australia, New Zealand, and other countries{{snd}}{{crossref|see {{section link|Currency symbols|dollar variants}}}}) use the full signifier (e.g. {{xt|US$}} or {{xt|A$}}, but not e.g. {{!xt|$US123}} or {{!xt|$123 (US)}}) each time, except (possibly) where a particular context makes this both unnecessary and undesirable.
* Cities: ]
** In articles entirely on US-related topics, all occurrences of the ] may be shortened ({{xt|$34}}), unless this would be unclear.
* Islands: ]
** For currencies that use a unit named the "]":
* Mountains: ]
*** Use the {{xt|£}} symbol ({{unichar|00A3|pound sign}}) for unambiguous referrals to ], the United Kingdom's currency. Avoid the {{!xt|{{unichar|20A4|lira sign}}}}.{{efn|Whether 00A3 is displayed with one or two bars is typeface (font) dependent.}}
*** {{xt|GBP}}, sterling's ISO 4217 code, should be used to disambiguate that currency from others. Avoid using {{xt!|stg.}} or {{xt!|GB£}}.{{efn|See also ].}}
*** For currencies other than sterling, use the symbol or abbreviation conventionally employed for that currency, if any.
* Link the first occurrence of lesser-known currency symbols (e.g. {{xt|]}})
* If there is no common English abbreviation or symbol, follow the ] standard. {{crossref|See also ].}}
{{see also|Misplaced Pages:Manual of Style/Abbreviations#Unicode abbreviation ligatures}}
{{Anchor|Formatting of monetary values}}'''Currency formatting'''


* A point (full stop or period, <code>.</code>){{snd}}never a comma{{snd}}is used as the decimal marker ({{xt|$6.57}}, not {{!xt|$6,57}}).
===Decimal degrees, minutes, or seconds===
* For the grouping of digits (e.g. {{xt|&pound;1,234,567}}) see {{section link||Grouping of digits}}, above.
* Do not place a currency symbol {{em|after}} the accompanying numeric figures (e.g. {{!xt|123$}}, {{!xt|123&pound;}}, {{!xt|123&euro;}}) unless that is the normal convention for that symbol when writing in English: {{xt|smaller British coins include 1p, 2p, and 5p denominations}}.
* Currency abbreviations preceding a numeric value are {{em|unspaced}} if they consist of a nonalphabetic symbol alone ({{xt|&pound;123}} or {{xt|&euro;123}}), or end with a nonalphabetic symbol ({{xt|{{R$|link=yes|123}}}}); but {{em|spaced}} (using {{t|nbsp}}) if completely alphabetic ({{xt|{{currency|123|ZAR}}}} or {{xt|{{currency|123|JOD}}}}).
* Ranges should be expressed giving the currency signifier just once: {{xt|{{val|p=$|250|{{ndash}}|300}}}}, not {{!xt|{{val|p=$|250}}{{ndash}}{{val|p=$|300}}}}.
* {{xt|million}} and {{xt|billion}} should be spelled out on first use, and (optionally) abbreviated {{xt|M}} or {{xt|bn}} (both unspaced) thereafter: {{xt|She received &pound;70 million and her son &pound;10M}}; {{xt|the school's share was {{val|p=$|250|{{ndash}}|300 |u=million}}, and the charity's $400{{ndash}}450M.}}
* In general, a currency symbol should be accompanied by a numeric amount e.g. not {{!xt|He converted his {{US$}} to {{A$}}}} but {{xt|He converted his US dollars to Australian dollars}} or {{xt|He exchanged the {{US$|100}} note for Australian dollars}}.
** Exceptions may occur in tables and infoboxes where space is limited e.g. {{xt|Currencies accepted: ], ], ], ]}}. It may be appropriate to wikilink such uses, or add an explanatory note.


'''Currency conversions'''{{anchor|Currency conversions}}
* degrees can be specified with decimals, in '''d''' mode
* Conversions of {{em|lesser-known currencies}} may be provided in terms of more familiar currencies{{snd}}such as the US dollar, euro or pound sterling{{snd}}using an appropriate rate (which is often {{em|not}} the current exchange rate). Conversions should be in parentheses after the original currency, along with the convert-to year; e.g. {{xt|the grant in 2001 was 10,000,000 ] ($1.4M, &euro;970,000, or &pound;850,000 {{as of|2009|lc=on}})}}
* minutes can be specified with decimals, in '''dm''' mode
* For {{em|obsolete currencies}}, provide an equivalent (formatted as a conversion) if possible, in the modern replacement currency (e.g. euros for amounts denominated in ]), or a US-dollar equivalent where there is no modern equivalent.
* seconds can be specified with decimals, in '''dms''' mode
* In some cases, it may be appropriate to provide a conversion accounting for inflation or deflation over time. {{crossref|See {{tlx|Inflation}} and {{tlx|Inflation-fn}}.}}
* When converting among currencies or inflating/deflating, it is rarely appropriate to give the converted amount to more than three significant figures; typically, only two significant figures are justified: {{xt|the grant in 2001 was 10,000,000 ] ($1.4M, &euro;970,000, or &pound;850,000)}}, not {{!xt|($1,390,570, &euro;971,673 or &pound;848,646)}}


==Common mathematical symbols<span id="Minus sign"></span>==
Example:
:<code><nowiki>{{coor d|12.0433|S|77.0283|W|}}</nowiki></code>
Which becomes {{coor d|12.0433|S|77.0283|W|}}


{{shortcut|WP:COMMONMATH||MOS:MINUS}}
===Attributes===
{{See also|Misplaced Pages:Manual of Style/Mathematics|Misplaced Pages:Manual of Style#Common mathematical symbols|Help:Displaying a formula}}
The final field, following the E/W, is available for specification of attributes, such as ''type'', ''region'' and ''scale''. For more information, see ].
* The ''Insert'' menu below the editing window gives a more complete list of math symbols, and allows symbols to be inserted without the HTML encoding (e.g. <code>&amp;divide;</code>) shown here.
* Spaces are placed to left and right when a symbol is used {{nobr|]}} ({{xt|the sum 4 + 5}}), but no space is used when {{nobr|]}} ({{xt|the value{{nbsp}}+5}}). ''Exception:'' spaces are usually omitted in inline fractions formed with <code>/</code>: {{xt|3/4}} not {{!xt|{{nobr|3 / 4}}}}.
* The {{tlx|mvar}} (for single-letter variables) and {{tlx|math}} (for more complicated expressions) templates are available to display mathematical formulas in a manner distinct from surrounding text.
* The {{tlx|nbsp}} and {{tlx|nowrap}} templates may be used to prevent awkward linebreaks.


{{clear right}}
===Note===
{|class="wikitable" style="align: center; text-align: center;"
''Due to planned enhancements in functionality, the above template concept is subject to change. As long as the above templates are adhered to, any necessary changes will be performed automatically by a robot.''
|+Common mathematical symbols
|-
! width=110|Symbol name
! width= 80|Example
! width=335|Markup
! Comments
|-
| rowspan=2| ]
| {{math|''x'' + ''y''}}
| <syntaxhighlight lang="wikitext" inline>{{math|''x'' + ''y''}}</syntaxhighlight>
| rowspan=2|
|-
| {{math|+''y''}}
| <syntaxhighlight lang="wikitext" inline>{{math|+''y''}}</syntaxhighlight>
|-
| rowspan=2|]
| {{math|''x'' &minus; ''y''}}
| <syntaxhighlight lang="wikitext" inline>{{math|''x'' &minus; ''y''}}</syntaxhighlight>
| rowspan=2|Do not use hyphens ({{!xt|<syntaxhighlight lang="wikitext" inline>-</syntaxhighlight>}}) or dashes ({{!xt|{{tlx|ndash}}}} {{nobr|or {{!xt|{{tlx|mdash}}}}).}}
|-
| {{math|&minus;''y''}}
| <syntaxhighlight lang="wikitext" inline>{{math|&minus;''y''}}</syntaxhighlight>
|-
| rowspan=2| ]
| 41.5 &plusmn; 0.3
| <syntaxhighlight lang="wikitext" inline>41.5 &plusmn; 0.3</syntaxhighlight>
| rowspan=2|
|-
| {{math|1={{nobr|1= &minus;(&plusmn;''a'') = &mnplus;''a''}}}}
| {{nobr|1=<syntaxhighlight lang="wikitext" inline>{{math|1=&minus;(&plusmn;''a'') = &#8723;''a''}}</syntaxhighlight> }}
|-
| ],<br>]
| {{math|''x'' &sdot; ''y''}}
| <syntaxhighlight lang="wikitext" inline>{{math|''x'' &sdot; ''y''}}</syntaxhighlight>
| rowspan=2|Do not use the letter {{!xt|x}} to indicate multiplication. However, an {{em|unspaced}} {{xt|x}} may be used as a substitute for "by" in common terms such as ].
|-
| ],<br>cross
| {{math|''x'' &times; ''y''}}
| <syntaxhighlight lang="wikitext" inline>{{math|''x'' &times; ''y''}}</syntaxhighlight>
|-
| ], ]
| {{math|''x'' &divide; ''y''}}
| <syntaxhighlight lang="wikitext" inline>{{math|''x'' &divide; ''y''}}</syntaxhighlight>
|
|-
| ]
| {{math|1=''x'' = ''y''}}
| <syntaxhighlight lang="wikitext" inline>{{math|1=''x'' = ''y''}}</syntaxhighlight> or<br><syntaxhighlight lang="wikitext" inline>{{math|''x'' {{=}} ''y''}}</syntaxhighlight>
| Note the use of <syntaxhighlight lang="wikitext" inline>1=</syntaxhighlight> or <syntaxhighlight lang="wikitext" inline>{{=}}</syntaxhighlight> to make the template parameters work correctly
|-
| ]
| {{math|''x'' &ne; ''y''}}
| <syntaxhighlight lang="wikitext" inline>{{math|''x'' &ne; ''y''}}</syntaxhighlight>
| rowspan=6|
|-
| ]
| {{math|''&pi;'' &asymp; 3.14}}
| <syntaxhighlight lang="wikitext" inline>{{math|''&pi;'' &asymp; 3.14}}</syntaxhighlight>
|-
| ]
| {{math|''x'' &lt; ''y''}}
| <syntaxhighlight lang="wikitext" inline>{{math|''x'' &lt; ''y''}}</syntaxhighlight>
|-
| ]
| {{math|''x'' &le; ''y''}}
| <syntaxhighlight lang="wikitext" inline>{{math|''x'' &le; ''y''}}</syntaxhighlight>
|-
| ]
| {{math|''x'' &gt; ''y''}}
| <syntaxhighlight lang="wikitext" inline>{{math|''x'' &gt; ''y''}}</syntaxhighlight>
|-
| ]
| {{math|''x'' &ge; ''y''}}
| <syntaxhighlight lang="wikitext" inline>{{math|''x'' &ge; ''y''}}</syntaxhighlight>
|}


==Geographical coordinates==
==Currency==
:''Competing/overlapping proposals: ] and/or ].''


{{Shortcut|MOS:COORDS|MOS:COORDINATES}}
In country-specific articles such as ] use only the symbol specific to the country, in this case $, with an italicized note placed at the top of the article to make this clear.


:{{crossref|For draft guidance on, and examples of, coordinates for linear features, see ].}}
In articles which are not country specific, such as ], use <code><nowiki>'']100''</nowiki></code> or <code><nowiki>''one hundred ]s''</nowiki></code>. Use the most commonly used English abbreviation, and link to the relevant article only at the first usage. If there is no common English abbreviation or symbol, use the ] standards.


:'''Quick guide''':
In countries where the euro is used, do not place "EU" or similar prefix before the € sign.


{{coord how-to}}
When a currency abbreviation is placed in front of a number, those which end in a symbol (such as ] or ]) should not be separated from the number. Those which end in an alphabetic character (such as ]) should be separated by a single, non-breaking space (<code>&amp;nbsp;</code>).
] on Earth should be entered using a template to standardise the format and to provide a link to maps of the coordinates. As long as the templates are adhered to, a robot performs the functions automatically.


First, ]. Avoid ].
===Conversions===


The {{tlx|Coord}} template offers users a choice of display format through ], emits a ], and is recognised (in the {{em|title}} position) by the "nearby" feature of Misplaced Pages's mobile apps and by external service providers such as Google Maps and Google Earth, and Yahoo. Infoboxes automatically emit {{tlx|Coord}}.
Conversions can be made into other currencies that are more familiar to most readers, such as the euro or United States dollar. Conversions should be in parentheses after the original currency, with the year given as a rough point of reference, for example, ''one thousand ] (approx. ]763, c.2005)'', rounding to the nearest whole unit.


The following formats are available.
===Examples===
* For degrees only (including decimal values): {{tlc|coord|2={{var|dd}}|3={{var|N/S}}|4={{var|dd}}|5={{var|E/W}}}}
* For degrees/minutes: {{tlc|coord|2={{var|dd}}|3={{var|mm}}|4={{var|N/S}}|5={{var|dd}}|6={{var|mm}}|7={{var|E/W}}}}
* For degrees/minutes/seconds: {{tlc|coord|2={{var|dd}}|3={{var|mm}}|4={{var|ss}}|5={{var|N/S}}|6={{var|dd}}|7={{var|mm}}|8={{var|ss}}|9={{var|E/W}}}}


where:
====Good style====
* {{var|dd}}, {{var|mm}}, {{var|ss}} are the degrees, minutes and seconds, respectively;
*]123
* {{var|N/S}} is either <kbd>N</kbd> for northern or <kbd>S</kbd> for southern ]s;
*]123
* {{var|E/W}} is either <kbd>E</kbd> for eastern or <kbd>W</kbd> for western ]s;
*]123 or ]&nbsp;123
* negative values may be used in lieu of <kbd>S</kbd> and <kbd>W</kbd> to denote Southern and Western ]
*]123
*]123
*]123
*]123
*123&nbsp;], ]&nbsp;123, or ]&nbsp;123


For example:
====Bad style====

*$123 — This can lead to ambiguity as to which dollar or peso is meant in articles that are not specific to one currency zone.
For the city of ], located at 59° 54&prime; 50&Prime; N, 10° 45&prime; 8&Prime; E:
*]123 — this is hard to read
: <code><nowiki>{{coord|59|54|50|N|10|45|08|E}}</nowiki></code>{{snd}}which becomes {{coord|59|54|50|N|10|45|08|E}}
*123$ — Although it is read aloud like this, this is not a standard way to write it. Dollars are sometimes written this way by Canadian francophones writing in English. Many other currencies are written this way, however.

*$123 (US)
For a country, like ], with no source on an exact geographic center, less precision is appropriate due to uncertainty:
*$US123
: <code><nowiki>{{coord|22|S|24|E}}</nowiki></code>{{snd}}which becomes {{coord|22|S|24|E}}

Higher levels of precision are obtained by using seconds:
: <code><nowiki>{{coord|33|56|24|N|118|24|00|W}}</nowiki></code>{{snd}}which becomes {{coord|33|56|24|N|118|24|00|W}}

Coordinates can be entered as decimal values:
: <code><nowiki>{{coord|33.94|S|118.40|W}}</nowiki></code>{{snd}}which becomes {{coord|33.94|S|118.40|W}}

Increasing or decreasing the number of decimal places controls the precision. Trailing zeros may be added as needed to give both values the same appearance.

], ], ] and ] are examples of articles that contain geographical coordinates.

Generally, the larger the object being mapped, the {{em|less precise}} the coordinates should be. For example, if just giving the location of a city, precision greater than degrees (°), minutes (&prime;), seconds (&Prime;) is not needed, which suffice to locate, for example, the central administrative building. Specific buildings or other objects of similar size would justify precisions down to 10{{nbsp}}meters or even one meter in some cases (1″ ~15{{nbsp}}m to 30{{nbsp}}m, 0.0001° ~5.6{{nbsp}}m to 10{{nbsp}}m).

The final field, following the E/W, is available for attributes such as <code>type:</code>, <code>region:</code>, or <code>scale:</code> {{crossref|(the codes are documented at {{section link|Template:Coord/doc#Coordinate parameters}})}}.

When adding coordinates, please remove the {{tlx|coord missing}} tag from the article, if present (often at the top or bottom).

{{Crossref|For more information, see ].}}

Templates other than {{tlx|coord}} should use the following variable names for coordinates: {{var|lat_d}}, {{var|lat_m}}, {{var|lat_s}}, {{var|lat_NS}}, {{var|long_d}}, {{var|long_m}}, {{var|long_s}}, {{var|long_EW}}.


==See also== ==See also==
* For ''page naming'' specifics, see ].


* ]
]
* ] at Meta
]
* {{section link|m:Help:Calculation|Displaying numbers and numeric expressions}} at Meta


==Notes==
]

]
{{Notelist|35em}}
]

]
==References==
]

{{Reflist|35em}}

{{Manual of Style}}
{{Math templates}}

]
]

Latest revision as of 13:28, 26 December 2024

Misplaced Pages project page "WP:NUMBERS" redirects here. For other uses, see WP:NUMBERS (disambiguation).
This guideline is a part of the English Misplaced Pages's Manual of Style.
It is a generally accepted standard that editors should attempt to follow, though occasional exceptions may apply. Any substantive edit to this page should reflect consensus. When in doubt, discuss first on the talk page.		Shortcuts
Manual of Style (MoS)

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Related guidelines

This page guides the presentation of numbers, dates, times, measurements, currencies, coordinates, and similar items in articles. The aim is to promote clarity, cohesion, and consistency, and to make the encyclopedia easier and more intuitive to use. For numbers, dates, and similar items in Misplaced Pages article titles, see the "Naming conventions (numbers and dates)" guideline.

Where this manual gives options, maintain consistency within an article unless there is a good reason to do otherwise. The Arbitration Committee has ruled that editors should not change an article from one guideline-defined style to another without a substantial reason unrelated to mere choice of style; edit-warring over optional styles is unacceptable. If discussion fails to resolve the question of which style to use in an article, defer to the style used by the first major contributor.

General notes

Quotations, titles, etc.

See also: Misplaced Pages:Manual of Style § Quotations

Quotations, titles of books and articles, and similar "imported" text should be faithfully reproduced, even if they use formats or units inconsistent with these guidelines or with other formats in the same article. If necessary, clarify via , article text, or footnotes.

Non-breaking spaces

Guidance on the use of non-breaking spaces ("hard spaces") is given in some sections below, but not all situations in which hard spaces ({{nbsp}} or &nbsp;) or {{nowrap}} may be appropriate are described. For further information see Misplaced Pages:Manual of Style § Non-breaking spaces and Misplaced Pages:Line-break handling.

Chronological items

Statements likely to become outdated

Shortcuts See also: Misplaced Pages:Manual of Style/Words to watch § Relative time references, Misplaced Pages:Updating information, and Misplaced Pages:As of

Except on pages that are inherently time-sensitive and updated regularly (e.g. the "Current events" portal), terms such as now, today, currently, present, to date, so far, soon, upcoming, ongoing, and recently should usually be avoided in favor of phrases such as during the 2010s, since 2010, and in August 2020. Wording can usually be modified to remove the "now" perspective: not she is the current director but she became director on 1 January 2024; not 2010–present but beginning in 2010 or since 2010. Terms likely to go out of date include best known for, holds the record for, etc. For current and future events, use phrases such as as of December 2024 or since the beginning of 2024 to signal the time-dependence of the information; use the template {{as of}} (or {{updated}}) in conjunction. Relative-time expressions are acceptable for very long periods, such as geological epochs: Humans diverged from other primates long ago, but only recently developed state legislatures.

Dates, months, and years

"WP:YEAR" redirects here. For WikiProject Years, see WP:YEARS. Shortcuts

Formats

Acceptable date formats
General use Only in limited situations
where brevity is helpful 		Comments
2 September 2001 2 Sep 2001 A comma doesn't follow the year unless otherwise required by context:
  • The 5 May 1922 meeting was cancelled.
  • Except Jones, who left London on 5 March 1847, every delegate attended the signing.
September 2, 2001 Sep 2, 2001 A comma follows the year unless other punctuation obviates it:
  • The weather on March 12, 2005, was clear and warm.
  • Everyone remembers July 20, 1969 – when humans first landed on the Moon.
2 September 2 Sep Omit year only where there is no risk of ambiguity:
  • The 2012 London Olympics ran from 25 July to 12 September.
  • January 1 is New Year's Day.
September 2 Sep 2
No equivalent for general use 2001-09-02 Use yyyy-mm-dd format only with Gregorian dates from 1583 onward.
September 2001 Sep 2001
Shortcut

Shortcuts

Unacceptable date formats (except in external titles and quotes)
Unacceptable Corrected Comments
Sep. 2 Sep 2 Do not add a full stop (period) to an abbreviated month or to the day-of-month.
9. June 9 June or June 9
9 june
june 9 		Months should be capitalized.
9th June
June 9th
the 9th of June 		Do not use ordinals (1st, 2nd, 3rd, etc.).
09-06
06-09 		Do not use these formats.
09 June
June 09 		Do not zero-pad day ...
2007-4-15 2007-04-15 ... except in all-numeric (yyyy-mm-dd) format, in which month and day are zero-padded to two digits.
2007/04/15 Do not use separators other than hyphens.
20070415 Do not omit hyphens.
07-04-15 Do not abbreviate year.
15-04-2007
04-15-2007
2007-15-04 		Do not use dd-mm-yyyy, mm-dd-yyyy or yyyy-dd-mm formats.
2007 April 15
2007 Apr 15 		Do not use these formats.
7/2001
7-2001
07-2001
2001-07
2001 July
July of 2001 		July 2001 Do not use these formats.
July, 2001 No comma between month and year.
3 July, 2001 3 July 2001
July 3 2001 July 3, 2001 Comma required between day and year.
the '97 elections
the 97 elections 		the 1997 elections Do not abbreviate year.
Copyright MMII Copyright 2002 Roman numerals are not normally used for dates.
Two thousand one 2001 Years and days of the month are not normally written in words.
the first of May
May the first 		1 May or May 1
June 0622 June 622 Do not zero-pad years.
June 2,015 June 2015 Do not add a comma to a four-digit year.
sold in the year 1995 sold in 1995 Write "the year" only where needed for clarity (About 200 ships arrived in the year 300).
Consistency

Shortcut
  • Dates in article body text should all use the same format: She fell ill on 25 June 2005 and died on 28 June, not She fell ill on 25 June 2005 and died on June 28.
  • Publication dates in an article's citations should all use the same format, which may be:
    • the format used in the article body text,
    • an abbreviated format from the "Acceptable date formats" table, provided the day and month elements are in the same order as in dates in the article body
    • the format expected in the citation style being used (but all-numeric date formats other than yyyy-mm-dd must still be avoided).
    For example, publication dates within a single article might be in one, but only one, of these formats (among others):
    • Jones, J. (20 September 2008)
    • Jones, J. (September 20, 2008)
    If an article uses a template such as {{Use mdy dates}} or {{Use dmy dates}}, then Citation Style 1 and 2 templates automatically render dates (|date=, |access-date=, |archive-date=, etc) in the specified format, regardless of the format they are entered in. (The |cs1-dates= parameter can be used to fine-tune the generated output, see Template:Use mdy dates § Auto-formatting citation template dates.)
  • Access and archive dates in an article's citations should all use the same format, which may be:
    • the format used for publication dates in the article (see above);
    • the format expected in the citation style adopted in the article; or
    • yyyy-mm-dd
    For example, access/archive dates within a single article might be in one, but only one, of these formats (among others):
    • Jones, J. (September 20, 2008) ... Retrieved February 5, 2009.
    • Jones, J. (20 Sep 2008) ... Retrieved 5 Feb 2009.
    • Jones, J. (20 September 2008) ... Retrieved 2009-02-05.
    When a citation style does not expect differing date formats, it is permissible to normalize publication dates to the article body text date format, and/or access/archive dates to either, with date consistency being preferred.
Strong national ties to a topic
Shortcut

For any given article, the choice of date format and the choice of national variety of English (see Misplaced Pages:Manual of Style § Strong national ties to a topic) are independent issues.

  • Articles on topics with strong ties to a particular English-speaking country should generally use the date format most commonly used in that nation. For the United States this is (for example) July 4, 1976; for most other English-speaking countries it is 4 July 1976.
  • Articles related to Canada may use either format with (as always) consistency within each article. (see Retaining existing format)
  • Shortcut In topics where a date format that differs from the usual national one is in customary usage, that format should be used for related articles: for example, articles on the modern US military, including biographical articles related to the modern US military, should use day-before-month, in accordance with US military usage.
Retaining existing format
Shortcuts See also: Misplaced Pages:Manual of Style § Retaining existing styles
  • If an article has evolved using predominantly one date format, this format should be used throughout the article, unless there are reasons for changing it based on the topic's strong ties to a particular English-speaking country, or consensus on the article's talk page.
  • The date format chosen in the first major contribution in the early stages of an article (i.e., the first non-stub version) should continue to be used, unless there is reason to change it based on the topic's strong ties to a particular English-speaking country, or consensus on the article's talk page.
  • Where an article has shown no clear sign of which format is used, the first person to insert a date is equivalent to "the first major contributor".

Era style

"WP:BCE" redirects here. For the copyediting guide, see Misplaced Pages:Basic copyediting. Shortcuts
  • The default calendar eras are Anno Domini (BC and AD) and Common Era (BCE and CE). Either convention may be appropriate for use in Misplaced Pages articles depending on the article context. Apply Misplaced Pages:Manual of Style § Retaining existing styles with regard to changes from one era to the other.
    • Use either the BC–AD or the BCE–CE notation consistently within the same article. Exception: do not change direct quotations, titles, etc.
    • An article's established era style should not be changed without reasons specific to its content; seek consensus on the talk page first (applying Misplaced Pages:Manual of Style § Retaining existing styles) by opening a discussion under a heading using the word era, or another similarly expressive heading, and briefly stating why the style should be changed.
    • BCE and CE or BC and AD are written in upper case, unspaced, without a full stop (period), and separated from the numeric year by a space (5 BC, not 5BC). It is advisable to use a non-breaking space.
    • AD appears before or after a year (AD 106, 106 AD); BCE, CE, and BC always appear after (106 CE, 3700 BCE, 3700 BC).
    • In general, omit CE or AD, except to avoid ambiguity or awkwardness.
      • Typically, write The Norman Conquest took place in 1066 not 1066 CE or AD 1066.
      • But Plotinus lived at the end of the 3rd century AD (not simply at the end of the 3rd century) may avoid confusion unless the era is clear from context.
      • One- and two-digit years may look more natural with an era marker (born in 2 AD or born January 15, 22 CE, not born in 2 nor January 15, 22).
      • Ranges beginning in BC / BCE should specify the ending era: write 450 to 200 BCE or 450 BC to 200 BC or 450 BCE to 200 CE, but not 450 BCE to 200. (see Ranges)
  • Uncalibrated (BCE) radiocarbon dates: Calibrated and uncalibrated dates can diverge widely, and some sources distinguish the two only via BCE or BC (for calibrated dates) versus bce or bc (uncalibrated). When feasible, avoid uncalibrated dates except in direct quotations, and even then ideally give the calibrated date in a footnote or square-bracketed note – , or at least indicate the date type – . This also applies to other dating systems in which a calibration distinction is drawn.
  • BP or YBP: In scientific and academic contexts, BP (Before Present) or YBP (years Before Present) are often used. (Present in this context by convention refers to January 1, 1950.) Write 3000 years BP or 3000 YBP or 3000 years before present but not forms such as 3000 before present and 3000 years before the present. If one of the abbreviated forms is used, link to Before Present on first use: The Jones artifact was dated to 4000 YBP, the Smith artifact to 5000 YBP.
  • Other era systems may be appropriate in an article. In such cases, dates should be followed by a conversion to Anno Domini or Common Era, and the first instance linked: Qasr-al-Khalifa was built in 221 AH (836 CE), or in 836 AD (221 AH).
    • Astronomical year numbering is similar to the Common Era. There is no need to follow a year expressed with astronomical year numbering with a conversion to Common Era. The first instance of a non-positive year should still be linked: The March equinox passed into Pisces in year −67. (The expressions −67 and 68 BCE refer to the same year.)

Julian and Gregorian calendars

Shortcuts See also: Old Style and New Style dates

A date can be given in any appropriate calendar, as long as it is (at the minimum) given in the Julian calendar or the Gregorian calendar or both, as described below. For example, an article on the early history of Islam may give dates in both Islamic and Julian calendars. Where a calendar other than the Julian or Gregorian is used, the article must make this clear.

  • Current events are dated using the Gregorian calendar.
  • Dates of events in countries using the Gregorian calendar at that time are given in the Gregorian calendar. This includes some of the Continent of Europe from 1582, the British Empire from 14 September 1752, and Russia from 14 February 1918 (see Adoption of the Gregorian calendar).
  • Dates before 15 October 1582 (when the Gregorian calendar was first adopted in some places) are normally given in the Julian calendar.
  • Dates after 4 October 1582 in a place where the Julian calendar was observed should be given in the Julian calendar.
  • For either the Julian or Gregorian calendars, the beginning of the year should be treated as 1 January even if a different start-of-year date was observed in the place being discussed.
  • Dates for Roman history before 45 BC are given in the Roman calendar, which was neither Julian nor Gregorian. When (rarely) the Julian equivalent is certain, it may be included.
  • For dates in early Egyptian and Mesopotamian history, Julian or Gregorian equivalents are often uncertain. Follow the consensus of reliable sources, or indicate their divergence.

The dating method used should follow that used by reliable secondary sources (or if reliable sources disagree, that used most commonly, with an explanatory footnote). The guidance above is in line with the usage of reliable sources such as American National Biography, Oxford Dictionary of National Biography, and Encyclopædia Britannica.

Where it is not obvious that a given date should be given in Julian alone or in Gregorian alone, consider giving both styles, for example by using {{OldStyleDate}}. If a date appears without being specified as Old Style or New Style, tagging that date with {{which calendar?}} will add the page to Category:Articles containing ambiguous dates for further attention.

If an article contains Julian calendar dates after 4 October 1582 (as in the October Revolution), or if a start-of-year date other than 1 January was in force in the place being discussed, or both, a footnote should be provided on the first usage, explaining the calendar usage adopted for the article. The calendar usage should be compatible with this guideline.

Ranges

Shortcuts See also: Misplaced Pages:Manual of Style § Number ranges "MOS:DIED" redirects here. For euphemisms for "died", see Misplaced Pages:Manual of Style/Words to watch § Euphemisms.
  • A simple year–year range is written using an en dash (–, &ndash; or {{ndash}}, or {{nbnd}} for a non-breaking en dash), not an em dash, hyphen, or slash; this dash is unspaced (that is, with no space on either side); and the end year is usually given in full:
    • 1881–1882;  1881–1886 (not 1881–86);  1881–1892 (not 1881–92)
      • Markup: 1881{{ndash}}1882 or 1881&ndash;1882
    • Although non-abbreviated years are generally preferred, two-digit ending years (1881–82, but never 1881–882 or 1881–2) may be used in any of the following cases: (1) two consecutive years; (2) infoboxes and tables where space is limited (using a single format consistently in any given table column); and (3) in certain topic areas if there is a very good reason, such as matching the established convention of reliable sources. For consistency, avoid abbreviated year ranges when they would be used alongside non-abbreviated ranges within an article (or related pages, if in titles). Never use abbreviated years for ranges across centuries (1999–2000, not 1999–00) or for years from the first millennium (886–887, not 886–87).
    • The slash notation (2005/2006) may be used to signify a fiscal year or other special period, if that convention is used in reliable sources.
  • Other "simple" ranges use an unspaced en dash as well:
    • day–day: 5–7 January 1979;  January 5–7, 1979;  elections were held March 5–8.
    • month–month: the 1940 peak period was May–July;  the peak period was May–July 1940;  (but the peak period was May 1940 – July 1940 uses a spaced en dash; see below)
  • In certain cases where at least one item on either side of the en dash contains a space, then a spaced en dash ({{snd}}) is used. For example:
    • between specific dates in different months: They travelled June 3 – August 18, 1952;  They travelled 3 June – 18 August 1952
    • between dates in different years:
      • Charles Robert Darwin (12 February 1809 – 19 April 1882) was an English naturalist ...
        • Markup: 12{{nbsp}}February 1809{{snd}}19{{nbsp}}April 1882 or 12&nbsp;February 1809&nbsp;&ndash; 19&nbsp;April 1882
      • Abraham Lincoln (February 12, 1809 – April 15, 1865) was the 16th president of ...
    • between months in different years: The exception was in force August 1892 – January 1903;  The Ghent Incursion (March 1822 – January 1, 1823) was ended by the New Year's Treaty
      • Markup: March 1822{{snd}}January{{nbsp}}1, 1823 or March 1822&nbsp;&ndash; January&nbsp;1, 1823
    • Where era designations, c. or other modifiers are present (see § Uncertain, incomplete, or approximate dates):
      • if the modifier applies to only one of the two endpoints of the range, use a spaced en dash: 150 BCE – 50 BCE, 5 BC – 12 AD, c. 1393 – 1414
      • if the modifier applies to the range as a whole, disregard the modifier: 150–50 BCE, reigned 150 BCE – 50 BCE, reigned 150–50 BCE, r. c. 1393 – 1414, r. 1393–1414.
  • Use an en dash, or a word such as from or between, but not both: from 1881 to 1886 (not from 1881–1886);  between June 1 and July 3 (not between June 1 – July 3)
Shortcuts

  • MOS:DATED says "terms such as ... 'present' should usually be avoided". For ranges, if "to present" or "–present" is used, the current year (or, in cases where necessary, date) of "present" at the time of writing should be included. Thus 1982–present (as of 2024) – if writing in 2024 – is preferable to 1982–present. If the "from" date has an internal space, a spaced en dash is used. Other constructions may be more appropriate in prose (see § Statements likely to become outdated). An alternative form is Since 1982.
In tables and infoboxes where space is limited, pres. may be used (1982–pres.). Do not use incomplete-looking constructions such as 1982– and 1982–... .
  • Consider adding the {{As of}}, or {{Update after}} templates to such constructions, depending on how important it is for editors to keep "present" up to date.

  • For a person still living: Serena Williams (born September 26, 1981) is a ..., not (September 26, 1981 – ) or (born on September 26, 1981).

    Do not use * to indicate born; use b. only where space is limited, e.g., in tables and infoboxes; use either born or b. consistently in any given table column.

  • Where birthdate is unknown: John Smith (died May 1, 1622) or John Smith (died 1622)

    Do not use † to indicate died; use d. only where space is limited, with consistency within any given table column.

  • An overnight period may be expressed using a slash between two contiguous dates: the night raids of 30/31 May 1942 or raids of 31 May / 1 June 1942.

    Or use an en dash: (unspaced) raids of 30–31 May 1942;  (spaced) raids of 31 May – 1 June 1942.

  • The {{Age}} template can keep ages current in infoboxes and so on:
    • {{age|1989|7|23}} returns: 35
    • {{age|1989|7|23}}-year-old returns: 35-year-old
    • {{age|1989|7|23}} years old returns: 35 years old
  • Date mathematics templates are available for other age calculations.

Uncertain, incomplete, or approximate dates

Shortcuts
  • To indicate "around", "approximately", or "about", the use of the {{circa}} template is preferred at first occurrence over just c. At later occurrences, c. is preferred over circa, c, ca, ca., around, approximately, or approx.:
    • John Sayer (c. 1750 – 2 October 1818) ...
    • the Igehalkid dynasty of Elam, c. 1400 BC ...
  • Where both endpoints of a range are approximate, c. should appear before each date (the two-argument form of {{circa}} does this):
    • Dionysius Exiguus (c. 470 – c. 540) ... (not Dionysius Exiguus (c. 470 – 540) ...)
    • Rameses III (reigned c. 1180 – c. 1150 BCE) ... (not Rameses III (reigned c. 1180 – 1150 BCE) ...)
  • Where birth/death limits have been inferred from known dates of activity:
    • Offa of Mercia (before 734 – 26 July 796) ...
    • Robert Menli Lyon (1789 – after 1863) ...
    • Ambrose Gwinnett Bierce (June 24, 1842 – after December 26, 1913) ...
  • When birth and death dates are unknown, but the person is known to have been active ("flourishing") during certain years, fl., ], or {{fl.}} may be used:
    • Jacobus Flori (fl. 1571–1588) ...
    • Jacobus Flori fils (fl. c. 1600 – 1616) ...
The corresponding template {{r.}} produces reign output: r. 540–562, though it is often clearer to write out reigned 540–562, especially in the lead. With both of these templates, linked forms should not be used on disambiguation pages, and "active" followed by the range is a better alternative for occupations not relating to the composition of works, whether it be musical, grammatical, historical, or any other such work.
  • When a date is known to be either of two years (e.g. from a regnal or AH year conversion, or a known age at death):
    • Anne Smith (born 1912 or 1913; died 2013) ...
  • Other forms of uncertainty should be expressed in words, either in article text or in a footnote: April 14, 1224 (unattested date). Do not use a question mark (1291?), because it fails to communicate the nature of the uncertainty.
  • Where c. or a similar form appears which applies only to one of the two endpoints of the range, use a spaced en dash ({{snd}}).
    • Examples: 1896 – after 1954, 470 – c. 540, c. 470 – 540, c. 470 – c. 540.
    • Markup: 1896{{snd}}after 1954, 470{{snd}}{{c.|540}}, {{c.|470}}{{snd}}540, {{c.|470|540}}.
  • Where a modifier applies to the range as a whole, such as fl. and r., use a spaced or unspaced en dash as appropriate to the range if this modifier is disregarded.
    • Examples: fl. 1571–1588, fl. c. 1600 – 1616, r. c. 1353 – 1336 BC, r. 1989–2019 CE, r. 2019 CE – present.
  • Some modifiers, such as traditionally, around, BH, and CE, sometimes apply to only one endpoint, and sometimes to the whole range. Whether the en dash should be spaced or unspaced should still be determined by the above guidelines, but consider rephrasing if the result is ambiguous or possibly confusing.
    • traditionally 1571–1588 and traditionally 1571 – 1588 mean two different things, which may not be obvious to the reader.
    • traditionally 1585 – c. 1590 can have two different meanings, and which one is meant may not be clear.
    • 400 BCE – 200 clearly has BCE applying only to one endpoint, but the range is ambiguous. Consider using 400–200 BCE, 400 BCE – 200 BCE, or 400 BCE – 200 CE, depending on what is meant.
    • Technically, Taishō 13 – 57 is currently unambiguous (because there is no Taishō 57), but it is better to use both era designations in this case: Taishō 13 – Shōwa 57.
  • Ideally a non-breaking space should follow very short modifiers such as c., fl., r., b., and d.

Times of day

Shortcuts

Context determines whether the 12- or 24-hour clock is used. In all cases, colons separate hours, minutes, and (where present) seconds, e.g. 1:38:09 pm or 13:38:09. Use figures (11 a.m. or 12:45 p.m.) rather than words (twelve forty-five p.m.).

  • 12-hour clock times end with lower-case a.m. or p.m., or am or pm, preceded by a non-breaking space, e.g. 2:30 p.m. or 2:30 pm (markup: 2:30{{nbsp}}p.m. or 2:30{{nbsp}}pm), not 2:30p.m. or 2:30pm. Hours should not have a leading zero (e.g. 2:30 p.m., not 02:30 p.m.). Usually, use noon and midnight rather than 12 pm and 12 am; whether "midnight" refers to the start or the end of a date should be explicitly specified unless clear from the context. Where several times that are all a.m. or all p.m. appear in close proximity, then a.m. or p.m. need be given only once if there is no risk of confusion.
  • 24-hour clock times have no a.m., p.m., noon or midnight suffix, and include a colon (15:30 not 1530). Hours under 10 should have a leading zero (08:15). The time 00:00 refers to midnight at the start of a date, 12:00 to noon, and 24:00 to midnight at the end of a date, but 24 should not be used for the first hour of the next day (e.g. use 00:10 for ten minutes after midnight, not 24:10).

Time zones

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Give dates and times appropriate to the time zone where an event took place. For example, the date of the attack on Pearl Harbor should be December 7, 1941 (Hawaii time/​date). Give priority to the place at which the event had its most significant effects; for example, if a hacker in Monaco attacked a Pentagon computer in the US, use the time zone for the Pentagon, where the attack had its effect. In some cases, the best solution may be to add the date and time in Coordinated Universal Time (UTC). For example:

     8 p.m. Eastern Standard Time on January 15, 2001 (01:00 UTC, January 16)

Alternatively, include just the UTC offset:

     21:00 British Summer Time (UTC+1) on 27 July 2012

Rarely, the time zone in which an event took place has since changed; for example, China until 1949 was divided into five time zones, whereas all of modern China is one time zone; UTC+8. Similarly, the term "UTC" is not appropriate for dates before this system was adopted in 1960; Universal Time (UT) is the appropriate term for the mean time at the prime meridian (Greenwich) when it is unnecessary to specify the precise definition of the time scale. Be sure to show the UTC or offset appropriate to the clock time in use at the time of the event, not the modern time zone, if they differ.

Days of the week

  • Where space is limited (e.g. tables), days of the week may be abbreviated as Sun, Mon, Tue, Wed, Thu, Fri, Sat (without dots, i.e. not Sun., Mon., etc.).

Seasons of the year

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  • Avoid using seasons to refer to a particular time of year, as they are often unduly ambiguous: Spring 1995 began in the Southern Hemisphere six months after it did in the Northern Hemisphere; winter spans two calendar years in the Northern Hemisphere, but not in the Southern Hemisphere. Moreover, areas near the Equator have only wet and dry seasons. Unambiguous alternatives include early 1995; the second quarter of 1995; March to June 1995; spent the southern autumn in Antarctica.
    • Referring to a season by name is appropriate when it is part of a conventional name or designation (annual mid-winter festival; the autumn harvest; the court's winter term; the magazine's summer 2015 issue).
  • Season names are generally not capitalized (a hot summer), except when personified (Old Man Winter) or when part of a formal name (2018 Winter Olympics; Arab Spring) that is capitalized under the guidelines for capitalization. They are capitalized when part of the title of a work (Science Fiction Quarterly, Summer 1942), except that seasonal editions may be lower-cased in running text (the Summer 1985 issue of Interzone or the summer 1985 issue of Interzone).

Decades

Shortcuts
  • To refer to a decade as a chronological period per se (not with reference to a social era or cultural phenomenon), always use four digits and an s, as in the 1980s. Do not use the 1980's, or the 1980‑ies.
    • Prefixes should be hyphenated (the mid‑1980s;  pre‑1960s social attitudes).
    • Adjectives should not be hyphenated (the late 1950s, the early 1970s).
  • For a social era or cultural phenomenon associated with a particular decade:
    • Two digits (with a preceding apostrophe) may be used as an alternative to four digits, but only in well-established phrases seen in reliable sources: the Roaring '20s; the Gay '90s; condemning the '60s counterculture—but grew up in 1960s Boston, moving to Dallas in 1971. Do not write: the 90's; the 90s; or the 90s'.
    • Another alternative (where seen in reliable sources) is to spell the decade out, capitalized: changing attitudes of the Sixties.

Centuries and millennia

Shortcuts

The sequence of numbered years in dates runs ... 2 BC, 1 BC, 1 AD, 2 AD ...; there is no "year zero".

  • Treat the 1st century AD as years 1–100, the 17th century as 1601–1700, and the second millennium as 1001–2000; similarly, the 1st century BC / BCE was 100–1 BC / BCE, the 17th century BC / BCE was 1700–1601 BC / BCE, and the second millennium 2000–1001 BC / BCE.
  • Centuries and millennia are identified using either Arabic numerals (the 18th century) or words (the second millennium), with in-article consistency (MOS:ORDINAL notwithstanding). When used adjectivally they contain a hyphen (nineteenth-century painting or 19th-century painting). Do not use superscripts (19 century).
  • Do not capitalize (the best Nineteenth-century paintings; during the Nineteenth Century)
  • Do not use Roman numerals (XVIII century).
  • The 18th century refers to the period (1701–1800), while strictly the 1700s refers either to (1700–1799) or (1700–1709)
    • When using forms such as the 1900s, ensure there is no ambiguity as to whether the century or the decade is meant.
  • See WP:Manual of Style § En dashes for use of hyphens and dashes in obscure situations.

Long periods of time

Numbers

"MOS:FIGURE" redirects here. Not to be confused with MOS:IMAGE.

Numbers as figures or words

Shortcuts

Information on specific situations is scattered elsewhere on this page.

Generally, in article text:

  • Integers from zero to nine are spelled out in words.
  • Integers greater than nine expressible in one or two words may be expressed either in numerals or in words (16 or sixteen, 84 or eighty-four, 200 or two hundred). When written as words, integers from 21 to 99 that are not multiples of 10 are hyphenated (including when part of a larger number): fifty-six and fifty-six thousand, but five hundred and five thousand.

Shortcut

Notes and exceptions:

  • Avoid beginning a sentence with a figure:
    • Use: There were many matches; 23 ended in a draw. Or: There were many matches. Twenty-three ended in a draw.
    • Not: There were many matches. 23 ended in a draw.
    • Use: No elections were held in 1945 and 1950.
    • Not: 1945 and 1950 had no elections. (Nor: Nineteen forty-five and 1950 had no elections—comparable numbers near one another should all be written in words or all in figures.)
  • In tables and infoboxes, quantities are expressed in figures (Years in office: 5); but numbers within a table's explanatory text and comments follow the general rule.
  • Numbers in mathematical formulae are never spelled out (3 < π < ⁠22/7⁠ not three < pi < twenty-two sevenths), and "numbers as numbers" are rarely spelled out in other mathematical contexts (the first three primes are 2, 3, and 5 not the first three primes are two, three, and five; but zero-sum game and roots of unity).
  • Sport scores and vote tallies should be given as numerical figures (a 25–7 victory; passed with 7 ayes, 2 nays, and 1 abstention, though passed with 7 ayes, 2 nays, and no abstentions would be acceptable, instead of ... 0 abstentions).
  • Comparable values near one another should be all spelled out or all in figures, even if one of the numbers would normally be written differently: patients' ages were five, seven, and thirty-two or ages were 5, 7, and 32, but not ages were five, seven, and 32.
    • Similar guidance applies where "mixed units" are used to represent a single value (as is often done with time durations, and in the imperial and US customary systems): 5 feet 11 inches tall; five feet eleven inches tall; 3 minutes 27 seconds; three minutes twenty-seven seconds.
  • Adjacent quantities not comparable should ideally be in different formats: twelve 90-minute volumes or 12 ninety-minute volumes, not 12 90-minute volumes or twelve ninety-minute volumes.
    • Avoid awkward juxtapositions: On February 25, 2011, twenty-one more were chosen, not On February 25, 2011, 21 more were chosen.
  • Sometimes figures and words carry different meanings; for example, Every locker except one was searched implies there is a single exception (without specifying which), while Every locker except 1 was searched implies that locker number 1 was the only locker not searched.
  • Proper names, technical terms, and the like are never altered: 10 Downing Street,  Nine Inch Nails,  Channel 8,  C7 vertebra,  The Sixth Sense,  Chanel No. 5,  Fourth Estate,  The Third Man,  Second Coming,  First Amendment,  Zero Hour!,  "Less than Zero".
  • Figures as figures: Use a figure when the figure itself (its glyph, shape, etc.) is meant: a figure-8 pattern; in the shape of the numeral 6. (See Misplaced Pages:Manual of Style/Text formatting § Words as words.)
  • Only figures are used with unit symbols (12 min not twelve min); but figures or words may be used with unit names (12 minutes or twelve minutes), subject to the provisions above.

Other numbers

  • Other numbers are given in numerals (3.75, 544) or in forms such as 21 million (or billion, trillion, etc. – but rarely thousand or hundred). Markup: 21{{nbsp}}million
    • Billion and trillion are understood to represent their short-scale values of 10 (1,000,000,000) and 10 (1,000,000,000,000), respectively. Keep this in mind when translating articles from non-English or older sources.
    • M (unspaced, capitalized) or bn (unspaced), respectively, may be used for "million" or "billion" after a number, when the word has been spelled out at the first occurrence (Her estate of £61 million was split among her husband (£1M), her son (£5M), her butler (£10M), and her three Weimaraners (£15M each).).
    • SI prefixes and symbols, such as mega- (M), giga- (G) and tera- (T), should be used only with units of measure as appropriate to the field and not to express large quantities in other contexts. Examples of misuse: In a population of 1.3G people, 300 megadeaths would be expected.
    • Sometimes, the variety of English used in an article may suggest the use of a numbering system other than the Western thousands-based system. For example, the Indian numbering system is conventionally used for certain things (especially monetary amounts) in South Asian English. This is discouraged in Misplaced Pages articles by WP:Manual of Style § Opportunities for commonality.
      • When it is done anyway, for contextually important reasons, link the first spelled-out instance of each quantity (e.g. ], which yields: crore). If no instances are spelled out, provide a note after the first instance, directing the reader to the article about the numbering system.
      • Provide a conversion to Western numbers for the first instance of each quantity (For Indian figures, the templates {{lakh}} and {{crore}} may be used for this purpose), and provide conversions for subsequent instances if they do not overwhelm the content of the article. For example, write three crore (thirty million). When converting a currency amount, use the exchange rate that applied at the time being written about; the {{FXConvert}} template can be used for this purpose, or specialized templates for a currency such as {{INRConvert}} (for Indian Rupees) or {{KRWConvert}} (for Korean Won) can be used.
      • Group digits in Western thousands-based style (e.g., 30,000,000; not 3,00,00,000); see § Delimiting (grouping of digits), below.
      • An article's variety of English does not uniquely determine its formatting of numbers. Other considerations – such as conventions used in mathematics, science, and engineering – may also apply. In general, choice and order of formats and conversions is a matter of editorial discretion and consensus at the article.
Shortcut

Ordinals

"MOS:1ST" redirects here. For the guideline on the first sentence in articles, see MOS:FIRST.
  • The general principles set out in § Numbers as figures or words apply to ordinals. In particular, do not start a sentence with a figure, and generally use first through ninth, not 1st through 9th, for single-digit ordinals.
  • In "suffix" forms, use two-letter suffixes: 1st, 2nd, 3rd, 4th and so on (2nd Battalion not 2d Battalion). Do not superscript (e.g. 123).
  • Do not use ordinals for dates (see MOS:BADDATE).
  • In English text, do not use a dot (.) or the ordinal indicator (º). The masculine º or feminine ª ordinal indicator is acceptable in names, quotations, etc. from languages that conventionally use it. An Italian example: 313º Gruppo Addestramento Acrobatico not 313º Acrobatic Training Group or the 313º. Use HTML markup for languages that do not have a special character but conventionally use a superscript, like 2 in French.
  • Regnal numbers are normally written with ASCII Roman numerals (without suffix, e.g. Elizabeth II not Elizabeth IInd or Elizabeth 2nd).

Number ranges

Shortcuts

Like date ranges, number ranges and page ranges should state the full value of both the beginning and end of the range, separated by an en dash: pp. 1902–1911 or entries 342–349. Except within quotations, avoid abbreviated forms such as 1902–11 or 342–9, which are not understood universally, are sometimes ambiguous, and can cause inconsistent metadata to be created in citations.

Sport scores, vote tallies, etc.

Shortcuts

Sport scores, vote tallies, or other presentations that juxtapose two opposing quantities use an unspaced en dash:

  • Smith beat Jones 7–3.
  • Polls predicted Alice would defeat Bob 74–20 percent, with 6 percent undecided.

To avoid potential line breaks, use {{nowrap}} around the entire score construction, or use {{nbnd}} instead of {{ndash}}.

Singular versus plural

  • Nouns following simple fractions are singular (took 1⁄4 dose;  net change was −1⁄2 point;  3⁄2 dose).
  • Nouns following mixed numbers are plural (11⁄2 doses;  another 43⁄4 miles).
  • Nouns following the lone, unsigned digit 1 (one) are singular, but those following other decimal numbers (i.e. base-10 numbers not involving fractions) are plural (increased 0.7 percentage points;  365.25 days;  paid 5 dollars per work hour, 1 dollar per travel hour, 0 dollars per standby hour;  increased by 1 point but net change +1 points;  net change −1 points;  net change 1.0 points).
  • The same rules apply to numbers given in words (one dose;  one and one-half doses;  zero dollars;  net change of negative one points).

Fractions and ratios

Shortcuts
  • Where numerator and denominator can each be expressed in one word, a fraction is usually spelled out (e.g. a two-thirds majority;  moved one-quarter mile); use figures if a fraction appears with a unit symbol (e.g. 1⁄4 mi (markup: {{frac|1|4}}&nbsp;mi), not a quarter of a mi or one-quarter mi). A common exception is a series of values: The distances were 1+1⁄4, 2⁄3 and 1⁄2 mile, respectively.
  • Mixed numbers may be given in figures or words (perhaps applying the guidance above to the integer part). If given in figures, they are unspaced (not Platform 9 3⁄4 or Platform 9-3⁄4 but Platform 9+3⁄4 (markup: {{frac|9|3|4}})). In any case the integer and fractional parts should be consistent (not Platform nine and 3⁄4).
  • Metric (SI) measurements generally use decimals, not fractions (5.25 mm, not 51⁄4 mm).
  • Non-metric (imperial and US customary) measurements may use fractions or decimals (51⁄4 inches; 5.25 inches); the practice of reliable sources should be followed, and within-article consistency is desirable.
  • In science and mathematics articles, mixed numbers are rarely used (use ⁠4/3⁠ the original voltage rather than 1⁠1/3⁠ times the original voltage). The use of {{frac}} is discouraged; instead use one of these styles:
    • 1 2 {\displaystyle \textstyle {\frac {1}{2}}} (markup: <math>\textstyle\frac{1}{2}</math>)
    • ⁠1/2⁠ (markup: {{sfrac|1|2}})
    • 1/2 (markup: 1/2)
  • Do not use precomposed fraction characters such as ½ (deprecated markup: &frac12; or &#189;).
  • Ordinal suffixes such as -th should not be used with fractions expressed in figures (not each US state has 1/50th of the Senate's votes; 1/8th mile, but one-fiftieth of the Senate's votes; 1/8 mile; one-eighth mile).
  • For dimensionless ratios (i.e. those without accompanying units), place a colon between integers, or place to between numbers-as-words: favored by a 3:1 ratio or a three-to-one ratio, not a 3/1 ratio or a 3–1 ratio. The same style is used to express odds in sport, gambling, and other statistical predictions.
    • Use a colon (spaced) when one or more decimal points is present (a 3.5 : 1 ratio (markup: a 3.5&nbsp;:&nbsp;1 ratio)).
    • Do not use the colon form where units are involved (dissolve using a 3 ml : 1 g ratio)‍—‌instead see ratios section of table at § Unit names and symbols, below.
See also: Misplaced Pages:Manual of Style/Mathematics § Fractions

Decimals

Shortcut
  • Use a period/full point (.) as the decimal separator, never a comma: 6.57, not 6,57.
  • Numbers between −1 and +1 require a leading zero (0.02, not .02); exceptions are sporting performance averages (.430 batting average) and conventional terms such as .22 caliber.
  • Although repeating digits may be indicated with an overbar (e.g. 14.31{{overline|28}} gives 14.3128), users of screen readers will not hear any indication of the overbar. Apart from in mathematics articles, consider rounding to a reasonable resolution instead (e.g. a half farthing ≈£0.00052 not £0.00052083, an inch ≈0.333 palms not 0.3 palms), or showing initial repeats before the overbar (e.g. 0.333). If overbars are used, consider explaining the notation on first use. Do not write e.g. 14.31(28) because it resembles notation for uncertainty.

Grouping of digits

Shortcut
  • In general, digits should be grouped and separated either by commas or by narrow gaps (never a period/full point).
    • Grouping with commas
      • Left of the decimal point, five or more digits are grouped into threes separated by commas (e.g. 12,200; 255,200 km; 8,274,527th; 1⁄86,400).
      • Numbers with exactly four digits left of the decimal point may optionally be grouped (either 1,250 or 1250), consistently within any given article.
      • Do not use commas to the right of the decimal point, or with numbers not in base 10.
      • Markup: {{formatnum:}} produces this formatting.
    • Grouping with narrow gaps
      • Digits are grouped both sides of the decimal point (e.g. 6543210.123456; 520.01234 °C; ⁠101325/760⁠).
      • Digits are generally grouped into threes. Right of the decimal point, usual practice is to have a final group of four in preference to leaving an "orphaned" digit at the end (99.1234567, but 99.1234567 would also be acceptable). In mathematics-oriented articles long strings may be grouped into fives (e.g. 3.14159265358979323846...).
      • This style is especially recommended for articles related to science, technology, engineering or mathematics, though in these contexts there may be cases in which grouping confuses rather than clarifies. (For example, for fractions written in horizontal format, adding spaces to a fraction like 123456/127 would cause it to be misread as 123⁠456/127⁠ or 1⁠23456/127⁠.)
      • Markup: Templates {{val}} or {{gaps}} may be used to produce this formatting. Note that use of any space character as a separator in numbers, including non-breaking space, is problematic for screen readers. (See § Non-breaking spaces.) Screen readers read out each group of digits as separate numbers (e.g. 30{{thin space}}000 is read as "thirty zero zero zero"). The output of {{val}} and {{gaps}} is compatible with screen readers.
  • Delimiting style should be consistent throughout a given article.
    • Either use commas or narrow gaps, but not both in the same article.
    • Either group the thousands in a four-digit number or do not, but not mixed use in the same article.
    • However, grouping by threes and fives may coexist.
  • Four-digit page numbers and four-digit calendar years should never be grouped (not sailed in 1,492, but dynasty collapsed around 10,400 BC or by 13727 AD, Vega will be the northern pole star).

Percentages

Shortcuts
  • Throughout scientific/​technical articles, and in tables and infoboxes in any article, the symbol % is generally preferred. Omit space (3%, not 3 %), and do not use mixed forms such as three %.
  • The body of non-scientific/​non-technical articles may use either the % symbol or the word(s) percent (American English) or per cent (British English): 10 percent; ten percent; 4.5 per cent.
  • Ranges are written 10–12%, ten to twelve per cent, or ten to twelve percent; not ten–twelve per cent, 10%–12%, or 10 to 12%.
  • When expressing the difference between two percentages, do not confuse a percentage change with a change in percentage points.

Scientific and engineering notation

Shortcuts
  • Scientific notation always has a single nonzero digit to the left of the point: not 60.22×10, but 6.022×10.
  • Engineering notation is similar, but with the exponent adjusted to a multiple of three: 602.2×10.
  • Avoid mixing scientific and engineering notations: A 2.23×10 m region covered by 234.0×10 grains of sand.
  • In a table column (or other presentation) in which all values can be expressed with a single power of 10, consider giving e.g. ×10 once in the column header, and omitting it in the individual entries. (Markup: {{e|7}})
  • In both notations, the number of digits indicates the precision. For example, 5×10 means rounded to the nearest thousand; 5.0×10 to the nearest hundred; 5.00×10 to the nearest ten; and 5.000×10 to the nearest unit.

Markup: {{val}} and {{e}} may be used to format exponential notation.

Uncertainty and rounding

Shortcuts
  • Where explicit uncertainty information (such as a margin of error) is available and appropriate for inclusion, it may be written in various ways:
    • (1.534 ± 0.035) × 10 m
    • 12.34 m ± 5% (not used with scientific notation)
    • 15.34
      −0.23 × 10 m
    • 1.604(48) × 10 J (equivalent to (1.604 ± 0.048) × 10 J)
    • Polls estimated Jones's share of the vote would be 55 percent, give or take about 3 percent
    • Markup: {{+-}}, {{su}}, and {{val}} may be used to format uncertainties.
  • Where explicit uncertainty is unavailable (or is unimportant for the article's purposes), round to an appropriate number of significant digits; the precision presented should usually be conservative. Precise values (often given in sources for formal or matter-of-record reasons) should be used only where stable and appropriate to the context, or significant in themselves for some special reason.
    • The speed of light is defined to be 299,792,458 m/s
    • but Particle velocities eventually reached almost two-thirds the 300-million-metre-per-second speed of light.
    • checks worth $250 (equivalent to $1,800 in 2016) (not $1,845.38 in 2016)
    • The city's 1920 population was 10,000 (not population was 9,996 – an official figure unlikely to be accurate at full precision)
    • but The town was ineligible because its official census figure (9,996) fell short of the statutory minimum of ten thousand (unusual case in which the full-precision official figure is truly informative)
    • The accident killed 337 passengers and crew, and 21 people on the ground (likely that accurate and precise figures were determined)
    • At least 800 persons died in the ensuing mudslides (unlikely that any precise number can be accurate, even if an official figure is issued)
    • or Officials listed 835 deaths, but the Red Cross said dozens more may have gone unreported (in reporting conflicting information, give detail sufficient to make the contrast intelligible)
    • The jury's award was $8.5 million (not $8,462,247.63). The appeals court reduced this to $3,000,001 (one dollar in actual damages, the remainder in punitive damages).
  • The number of decimal places should be consistent within a list or context (The response rates were 41.0 and 47.4 percent, respectively, not 41 and 47.4 percent), unless different precisions are actually intended.
  • It may sometimes be appropriate to note the lack of uncertainty information, especially where such information is normally provided and necessary for full interpretation of the figures supplied.
    • A local newspaper poll predicted 52 percent of the vote would go to Smith, but did not include information on the uncertainty of this estimate
  • The {{undue precision}} template may be added to figures appearing to be overprecise.
  • Avoid using "approximately", "about", and similar terms with figures that have merely been approximated or rounded in a normal and expected way, unless the reader might otherwise be misled.
    • The tallest player was 6 feet 3 inches (not ... about 6 feet 3 inches – heights are conventionally reported only to the nearest inch, even though greater precision may be available in principle)
    • but The witness said the assailant was about 5 feet 8 inches tall ("about" because here the precise value is unknown, with substantial uncertainty)
  • The reader may be assumed to interpret large round numbers (100,000 troops) as approximations. Writing a quantity in words (one hundred thousand troops), especially if the indefinite article (a/an) is used instead of the word one (a hundred thousand troops), can further emphasize its approximate nature.
  • See § Unit conversions below for precision issues when converting units.

Non–base-10 notations

Shortcuts
  • In computer-related articles, use the prefix 0x for hexadecimal and 0b for binary, unless there is a strong reason to use some other notation. Explain these prefixes in the article's introduction or on first use.
  • In all other articles, use {{base}}: 1379, 2013. Markup: {{base|137|9}}, {{base|201|3}}
  • For bases above 10, use symbols conventional for that base (as seen in reliable sources) e.g. for base 16 use 0–9 and A–F.
  • For octal, use 2008. Avoid using a prefix unless it is needed for computer code samples, in which case explain the prefix on first use.

Mathematical formulae

Main page: Misplaced Pages:Manual of Style/Mathematics

There are multiple ways to display mathematical formulae, covered in detail at Misplaced Pages:Manual of Style/Mathematics § Typesetting of mathematical formulae. One uses special MediaWiki <math>...</math> markup using LaTeX syntax, which is capable of complex formulae; the other relies on conventionalized HTML formatting of simple formulae.

The <math> markup is displayed as a PNG image by default. Logged-in users can optionally have it rendered in MathML, or in HTML (via MathJax); detailed instructions are at Help:Displaying a formula.

Do not put <math> markup in headings.

Units of measurement

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Unit choice and order

Quantities are typically expressed using an appropriate "primary unit", displayed first, followed, when appropriate, by a conversion in parentheses e.g. 200 kilometres (120 mi). For details on when and how to provide a conversion, see the section § Unit conversions. The choice of primary units depends on the circumstances, and should respect the principle of strong national ties, where applicable:

  • In non-scientific articles with strong ties to the United States, the primary units are US customary (pounds, miles, feet, inches, etc.)
  • In non-scientific articles with strong ties to the United Kingdom, the primary units for most quantities are metric or other internationally used units, except that:
    • UK engineering-related articles, including those on bridges and tunnels, generally use the system of units in which the subject project was drawn up (but road distances are given in imperial units, with a metric conversion – see next bullet);
    • the primary units for distance/​length, speed and fuel consumption are miles, miles per hour, and miles per imperial gallon (except for short distances or lengths, where miles are too large for practical use);
    • the primary units for personal height and weight are feet​/inches and stones/​pounds;
    • imperial pints are used for quantities of draught beer/​cider and bottled milk;
  • In all other articles, the primary units chosen will be SI units (such as kilograms), non-SI units officially accepted for use with the SI, or such other units as are conventional in reliable sources discussing the article topic (such as revolutions per minute (rpm) for rotational speed, hands for heights of horses, mass and luminosity of the Sun, etc.)
    • the primary SI units for personal height and weight are centimetres and kilograms.

Special considerations:

  • Quantities set via definition (as opposed to measured quantities) should be given first in the units used in the definition, even if this makes the structure of presentation inconsistent: During metrication, the speed limit was changed from 30 mph (48 km/h) to 50 km/h (31 mph).
    • Or use about to emphasize which is the statutory, exact value: ...from 30 mph (about 48 km/h) to 50 km/h (about 31 mph).
  • Nominal quantities (e.g. 2 × 4 lumber) require consideration of whether the article is concerned with the item's actual dimensions or merely with its function. In some cases, the nominal quantity may suffice; in others it may be necessary to give the nominal size (often in non-SI units), the actual size in non-SI units, and the actual size in SI units.
  • Whenever a conversion is given, the converted quantity's value should match the precision of the source (see § Unit conversions).
  • Where the article's primary units differ from the units given in the source, the {{convert}} template's |order=flip flag can be used; this causes the original unit to be shown as secondary in the article, and the converted unit to be shown as primary: {{convert|200|mi|km|order=flip}} → The two cities are 320 kilometres (200 mi) apart.

Unit conversions

See also: § Currency conversions, and Misplaced Pages:WikiProject Astronomy/Manual of Style § Units Shortcuts

Where English-speaking countries use different units for the same quantity, provide a conversion in parentheses: the Mississippi River is 2,320 miles (3,734 km) long; the Murray River is 2,508 kilometres (1,558 mi) long. But in science-related articles, supplying such conversion is not required unless there is some special reason to do so.

  • Where an imperial unit is not part of the US customary system, or vice versa – and in particular, where those systems give a single term different definitions – a double conversion may be appropriate: Rosie weighed 80 kilograms (180 lb; 12 st 8 lb) (markup: {{convert|80|kg|lb stlb}}); The car had a fuel economy of 5 L/100 km (47 mpg‑US; 56 mpg‑imp) (markup: {{convert|5|L/100km|mpgus mpgimp|abbr=on}}).
  • Generally, conversions to and from metric units and US or imperial units should be provided, except:
    • When inserting a conversion would make a common or linked expression awkward (The four-minute mile).
    • In some topic areas (for example, maritime subjects where nautical miles are the primary units, American football where yards are primary, and articles like Solar System where many interplanetary distances are given) it can be excessive to provide a conversion for every quantity. In such cases consider noting that the article will use a particular unit – possibly giving the conversion factor to other, familiar units in a parenthetical note or a footnote – and link the first occurrence of each unit but not give a conversion every time it occurs. Applying this principle may require editorial discretion; for example, in scientific articles the expected level of reader sophistication should be taken into account.
    • For distances on the scale of between star systems and galaxies, "light-years" or "ly" should be used as primary units, with a conversion to "parsecs" or "pc", but no conversion to SI units. The units should be linked on first mention. For larger quantities, use large number words in prose (million or billion but not thousand) and metric prefixes (kly, Mly, Gly, kpc, Mpc, Gpc) in compact contexts. Examples:
      • First mention in prose: 34.6 ± 2.3 million light-years (10.6 ± 0.705 Mpc)
        • Wikitext: {{convert|34.6|±|2.3|e6ly|Mpc|sigfig=3|lk=on}}
      • Infobox or table: 2.50 Mly (765 kpc)
        • Wikitext: {{cvt|765|kpc|Mly|order=flip|sigfig=3|lk=on}} (use "order=flip" when source uses parsecs)
    • Astronomical units (au) should be converted to kilometers (km) using "million", "billion", or "trillion" in both prose and compact environments like infoboxes and tables. When large interplanetary-scale distances overlap with small interstellar-scale distances, convert au to ly and pc, or ly to pc and au (depending on context). Examples:
      • 49.3 au (7.38 billion km)
        • Wikitext: {{convert|49.3|au|e9km|abbr=unit}}
      • 121,000 astronomical units (1.91 light-years; 0.59 parsecs)
        • Wikitext: {{convert|121000|au|ly pc|abbr=off|lk=on}}
      • 0.9 ly (0.28 pc; 57,000 au)
        • Wikitext: {{convert|0.9|ly|pc au|abbr=unit}}
  • For units of measure that are obsolete, obscure outside of a particular specialty or geography (e.g. furlong, jansky, or rayleigh), or not part of the SI/SI-accepted or US customary systems (e.g. zolotnik), supply a parenthetical conversion into at least SI or SI-accepted units (unless one of the exceptions previously noted applies). Convert each mention, unless this would be excessive given the context. Take care to distinguish between different definitions of the same unit if it has changed over time or differs geographically (e.g. cubit, batman). An approximate or range conversion is acceptable if the exact historical value is uncertain (e.g. stadion).
    • Metric units not part of the SI or accepted for use with it should either be replaced with SI or SI-accepted units (e.g. joules instead of ergs), or they should be treated as obscure units in the same way as furlongs.
  • Metric prefixes used should be commonly known, namely "pico" thru "tera", preferably in commonly-used combinations (e.g. 2,000 kilometers not 2 megameters).
  • Converted quantity values should use a level of precision similar to that of the source quantity value, so the Moon is 380,000 kilometres (240,000 mi) from Earth, not (236,121 mi). Small numbers, especially if approximate, may need to be converted to a range where rounding would cause a significant distortion, so about one mile (1–2 km), not about one mile (2 km). Be careful especially when your source has already converted from the units you're now converting back to. This may be evidenced by multiples of common conversion factors in the data, such as 160 km (from 100 miles). See false precision.
  • {{convert}} and other conversion templates can be used to convert and format many common units, and have options to respect significant figures. To avoid problems with rounding and significant figures, for input to conversion templates use only the original quantity found in reliable sources, not one that a source has already converted. If required by the above rules, the conversion output can be displayed as the primary units with "order=flip". Conversion output can be displayed as the only units with "disp=out"; this retains the original quantity in wikitext for verification by editors.
  • In a direct quotation, always retain the source units. Any conversions can be supplied either in the quote itself (in square brackets, following the original measurement) or in a footnote. See footnoting and citing sources.
  • {{Units attention}} may be added to articles needing general attention regarding choice of units and unit conversions.

Unit names and symbols

"WP:DEGREE" redirects here. For the essay on notability, see WP:POSITION. Shortcuts
Definitions:
  • Examples of unit names: foot, metre, kilometre, (US: meter, kilometer).
  • Examples of unit symbols: ft, m, km.
  • Unit names and symbols should follow the practice of reliable sources.
  • In prose, unit names should be given in full if used only a few times, but symbols may be used when a unit (especially one with a long name) is used repeatedly, after spelling out the first use (e.g. Up to 15 kilograms of filler is used for a batch of 250 kg).
    • Exception: Certain units are generally represented by their symbols (e.g. °C rather than degrees Celsius) even on first use, though their unit names may be used for emphasis or clarity (conversion of degrees Celsius to degrees Fahrenheit).
    • Exception: Consider using inches (but not in.) in place of in where the latter might be misread as a preposition‍—‌but not where the value is followed by a parenthesized conversion e.g. bolts 5 in (12.7 cm) long, or is part of such a conversion (bolts 12.7 cm (5 in) long).
  • Where space is limited, such as in tables, infoboxes, parenthetical notes, and mathematical formulas, unit symbols are preferred.
  • Units unfamiliar to general readers should be presented as a name–symbol pair on first use, linking the unit name (Energies rose from 2.3 megaelectronvolts (MeV) to 6 MeV).
    • Commonly-known SI and SI-accepted units that can be used without linking are: meter (m), gram (g), second (s), ampere (A), liter (L), pascal (Pa), hertz (Hz), degrees Celsius (°C), minute (min), hour (h), day (d), degree (of angle, °), volt (V), watt (W)
  • Ranges use unspaced en dash ({{ndash}}) if only one unit symbol is used at the end (e.g. 5.9–6.3 kg), and spaced en dash ({{snd}}) if two symbols are used (e.g. 3 μm – 1 mm); ranges in prose may be specified using either unit symbol or unit names, and units may be stated either after both numerical values or after the last (all acceptable: from 5.9 to 6.3 kilograms; from 5.9 kilograms to 6.3 kilograms; from 5.9 to 6.3 kg; from 5.9 kg to 6.3 kg).
  • Length–width, length–width–height and similar dimensions may be separated by the multiplication sign (× or &times;) or the word by.
    • The × symbol is preceded by a space (preferably non-breaking), and followed by a space (which may also be non-breaking in short constructions), and each number should be followed by a unit name or symbol:
      • 1 m × 3 m × 6 m, not 1 × 3 × 6 m, (1 × 3 × 6) m, nor 1 × 3 × 6 m
      • a metal plate 1 ft × 3 ft × 0.25 in
      • a railroad easement 10 ft × 2.5 mi
    • With by, the unit need be given only once if it is the same for all dimensions: 1 by 3 by 6 metres or 1 by 3 by 6 m.
    • The unspaced letter x may be used in common terms such as 4x4.
General guidelines on use of units
Aspect Guideline Acceptable Unacceptable
Unit names and symbols Except as listed in the § Specific units table below, unit symbols are uncapi­tal­ized unless they are derived from a proper name, in which case the first letter (of the base unit symbol, not of any prefix) is capitalized. 8 kg
100 kPa 		8 Kg
100 kpa
Unit symbols are undotted. 38 cm of rope 38 cm. of rope
Unit names are given in lower case except: where any word would be capital­ized, or where otherwise specified in the SI brochure or this Manual of Style.
  • A gallon is 4 quarts.
  • 4 pascals
  • A Gallon is 4 Quarts.
  • 4 Pascals
  • He walked several miles.
  • Miles of trenches were dug.
The spelling of certain unit names (some of which are listed in § Specific units, below) varies with the variety of English followed by the article.
Write unit names and symbols in upright (roman) type, except where emphasizing in context. 10 m
29 kilograms 		10 m
29 kilograms
Thus each two-liter jug contained only two quarts.
Do not use precomposed unit symbol characters. ㎓, ㎦, ㎍, ㎖, ㎉
Numeric values Do not spell out numbers before unit symbols ... 12 min twelve min
... but words or figures may be used with unit names.
  • twelve minutes
  • 12 minutes
Use a non-breaking space ({{nbsp}} or &nbsp;) between a number and a unit symbol, or use {{nowrap}} ... 29 kg (markup: 29&nbsp;kg or {{nowrap|29 kg}}) 29kg
... though with certain symbols no space is used (see "Specific units" table below) ... 23° 47′ 22″ 23 ° 47 ′ 22 ″
... and a normal space is used between a number and a unit name. 29 kilograms
(markup: 29 kilograms)
To form a value and a unit name into a compound adjective use a hyphen or hyphens ...
  • a five-day holiday
  • a five-cubic-foot box
  • a 10-centimeter blade
... but a non-breaking space (never hyphen) separates a value and unit symbol.
  • a blade 10 cm long
 a 10-cm blade
Plurals SI unit names are pluralized by adding -s or -es ... 1 ohm; 10 ohms
... except for these irregular forms. 1 henry; 10 henries
1 hertz; 10 hertz
1 lux; 10 lux
1 siemens; 10 siemens 		10 henrys
10 hertzes
10 luxes
10 siemenses
Some non-SI units have irregular plurals. 1 foot; 10 feet 10 foots
1 stratum; 10 strata (unusual) 10 stratums
Unit symbols (in any system) are identical in singular and plural.
  • grew from 1 in to 2 in
  • grew from 1 inch to 2 inches
  • grew from one to two inches
grew from 1 in to 2 ins
Powers Format exponents using <sup>, not special characters. km
(markup: km<sup>2</sup>) 		km²
(km&#178;)
Or use squared or cubed (after the unit being modified). ten metres per second squared ten metres per squared second
For areas or volumes only, square or cubic may be used (before the unit being modified). ten metres per square second
tons per square mile
sq or cu may be used with US customary or imperial units, but not with SI units. 15 sq mi
3 cu ft 		15 sq km
3 cu m
Products Indicate a product of unit names with either a hyphen or a space.
  • foot-pound
  • foot pound
  • footpound
  • foot⋅pound
Indicate a product of unit symbols with &sdot; or &nbsp;.
  • ms = millisecond
  • m⋅s or m s = metre-second
Exception: In some topic areas, such as power engineer­ing, certain products take neither space nor &sdot;. Follow the practice of reliable sources in the article's topic area.
To pluralize a product of unit names, pluralize only the final unit. (Unit symbols are never pluralized.) ten foot-pounds ten feet-pounds
Ratios, rates, densities Indicate a ratio of unit names with per. meter per second meter/second
Indicate a ratio of unit symbols with a forward slash (/), followed by either a single symbol or a parenthesized product of symbols – do not use multiple slashes. Or use , , etc.
  • metre per second
  • m/s
  • m⋅s
  • mps
  • kg/(m⋅s)
  • kg⋅m⋅s
  • kg/m⋅s
  • kg/m/s
To pluralize a ratio of unit names, pluralize only the numerator unit. (Unit symbols are never pluralized.)
  • ten newton-metres per second
  • 10 N⋅m/s
Some of the special forms used in the imperial and US customary systems are shown here ...
  • mph = miles per hour
  • mpg = miles per gallon
  • psi = pounds per square inch
... but only the slash or negative exponent notations are used with SI (and other metric) units.
  • g/m
  • g⋅m
 gsm
  • km/h
  • km⋅h
 kph
Prefixes Prefixes should not be separated by a space or hyphen. kilopascal
  • kilo pascal
  • kilo-pascal
Prefixes are added without contraction, except as shown here: kilohm
megohm
hectare 		kiloohm
megaohm
hectoare
The deci-, deca-, and hecto- prefixes should generally be avoided; exceptions include decibel, hectolitre, hectare, and hectopascal.
  • 100 metres
  • 0.1 km
 1 hectometre
Do not use M for 10, MM for 10, or B for 10 (except as noted elsewhere on this page for M and B, e.g. for monetary values) 3 km
8 MW
125 GeV 		3 Mm
8 MMW
125 BeV
Mixed units Mixed units are traditionally used with the imperial and US customary systems ...
  • a wall 1 ft 1 in thick
  • a wall 1 foot 1 inch thick
  • a man 6 feet 2 inches tall
  • a 6-foot 2-inch man
  • a 6 ft 2 in man
  • 1 ft , 1 in (no comma)
  • 1 foot , 1 inch
  • a man 6 foot 2 tall
  • a 6-foot 2 man
  •  
  • 1 US fl pt 8 oz
  • 1 US fl pt 8 US fl oz
... and in expressing time durations ...
  • 1:30:07
  • 1:30 
  • 1 h 30 min 7 s
  • 01 30 07 
  • 1:30′07″
  • 1:30′
  • 1 hr 30 min 7 sec
  • 1 h 30 m 7 s
... but are not used with metric units.
  • 1.33 m
  • 133 cm
1 m 33 cm

Note to table:

  1. Use this format only where it is clear from context whether it means hours and minutes (HH:MM) or minutes and seconds (MM:SS).
  2. This format is used in astronomy (see the IAU Style Manual for details).

Specific units

Shortcuts
  • The following table lists only units that need special attention.
  • The SI Brochure should be consulted for guidance on use of other SI and non-SI units.
Guidelines on specific units
Group Unit name Unit symbol Comment
Length, speed
  • inch
  • foot
  • in
  • ft
 Do not use &prime; (′), &Prime; (″), apostrophe ('), or quote ("). Exception: in music, eight-foot pitch notation describes organ stops and wind instrument lengths in feet. A prime may be used with an explanation on first use, e.g. a 16 foot (16′) organ pedal stop; see MOS:MUSIC.
foot per second ft/s (not fps)
hand h or hh Equal to 4 inches; used in measurement of horses. A dot may be followed by additional inches e.g. 16.2 hh indicates 16 hands 2 inches.
  • kn (not kt, Kt, or kN)
  • KIAS or kn
  • KCAS
  • KEAS
  • KTAS
  • kn (not KGS)
 Used in aviation contexts for aircraft and wind speeds, and also used in some nautical and general meteorological contexts. When applied to aircraft speeds, kn means KIAS unless stated otherwise; if kn is used for calibrated airspeed, equivalent airspeed, true airspeed, or groundspeed, explicitly state and link to, upon first use, the type of speed being referred to (for instance, kn equivalent airspeed, or, if severely short of space, kn EAS); for airspeeds other than indicated airspeed, the use of the specific abbreviation for the type of airspeed being referred to (such as KEAS) is preferred. When referring to indicated airspeed, either kn or KIAS is permissible. Groundspeeds and wind speeds must use the abbreviation kn only.
  • metre
  • meter (US)
 m
micron μm (not μ) Markup: &mu;m  Link to micrometre (for which micron is a synonym) on first use.
astronomical unit au
(not A.U., ua) 		The preferred form is au. Articles that already use AU may switch to au or continue with AU; seek consensus on the talk page.
  • mile
  • miles per hour
  • nautical mile
  • mi
  • mph
  • nmi or NM (not nm or M)
In nautical and aeronautical contexts where there is risk of confusion with nautical miles, consider writing out references to statute miles as e.g. 5 statute miles rather than simply 5 miles.
Volume, flow
  • cubic centimetre
  • cubic centimeter (US)
cm Markup: cm<sup>3</sup>
cc Non-SI abbreviation used for certain engine displacements. Link to Cubic centimetre on first use.
  • imperial fluid ounce
  • imperial pint
  • imperial quart
  • imperial gallon
  • US fluid ounce
  • US dry pint
  • US liquid pint
  • US dry quart
  • US liquid quart
  • US gallon
  • imp fl oz
  • imp pt
  • imp qt
  • imp gal
  • US fl oz
  • US dry pt
  • US liq pt
  • US dry qt
  • US liq qt
  • US gal
  • US or imperial (or imp) must be specified for all these units.
  • fluid or fl must be specified for fluid ounces (to avoid ambiguity versus avoirdupois ounce and troy ounce).
  • For US pints and quarts, dry or liquid (liq) are needed to be fully unambiguous, though context determines whether or not to repeat those qualifiers on every use in a given article.
cubic foot cu ft (not cf) Write five million cubic feet, 5,000,000 cu ft, or 5×10 cu ft, not 5 MCF.
cubic foot per second cu ft/s (not cfs)
  • litre
  • liter (US)
 L (not l or ℓ) The symbol l (lowercase "el") in isolation (i.e. outside forms as ml) is easily mistaken for the digit 1 or the capital letter I ("eye") and should not be used.
  • millilitre
  • milliliter (US)
 ml or mL Derivative units of the litre may use l (lowercase "el").
Mass, weight, force, density, pressure
  • gram
  • kilogram
  • g
  • kg
 Not gramme, kilogramme
  • long ton
  • short ton
 Spell out in full.
t (not mt, MT, or Mt)
pound per square inch psi
  • troy ounce
  • troy pound
  • oz t
  • lb t
 The qualifier t or troy must be specified where applicable. Use the qualifier avdp (avoirdupois) only where there is risk of confusion with troy ounce, imperial fluid ounce, US fluid ounce, or troy pound; but articles about precious metals, black powder, and gemstones should always specify which type of ounce (avoirdupois or troy) is being used, noting that these materials are normally measured in troy ounces and grams.
  • avoirdupois ounce
  • avoirdupois pound
  • oz or oz avdp
  • lb or lb avdp
carat carat Used to express masses of gemstones and pearls.
Purity carat or karat k or Kt (not kt or K) A measure of purity for gold alloys. (Do not confuse with the unit of mass with the same spelling.)
Time
  • second
  • minute
  • hour
  • s
  • min
  • h
 Do not use &prime; (′), &Prime; (″), apostrophe (') or quote (") for minutes or seconds. See also the hours–minutes–seconds formats for time durations described in the Unit names and symbols table.
year a Use a only with an SI prefix multiplier (a rock formation 540 Ma old, not Life expectancy rose to 60 a).
y or yr See § Long periods of time for all affected units.
Information, data bit bit (not b or B) See also § Quantities of bytes and bits, below. Do not confuse bit/second or byte/second with baud (Bd).
byte B or byte (not b or o)
bit per second bit/s (not bps, b/s)
byte per second B/s or byte/s (not Bps, bps, b/s)
Angle
arcminute ′ Markup: {{prime}}  (prime ′ not apostrophe/​single quote '). No space (47′, not 47 ′).
arcsecond ″ Markup: {{pprime}}  (double prime ″ not double-quote "). No space (22″, not 22 ″).
degree ° Markup: degree ° not masculine ordinal º or ring  ̊. No space (23°, not 23 °).
Temperature degree Fahrenheit °F (not F) Markup: 12{{nbsp}}°C, not 12°C or 12°{{nbsp}}C . Do not use the precomposed characters U+2103 ℃ DEGREE CELSIUS or U+2109 ℉ DEGREE FAHRENHEIT.
degree Rankine °R (not R)
degree Celsius (not degree centigrade) °C (not C)
kelvin (not degree kelvin) K (not °K) Use a non-breaking space: 12{{nbsp}}K (use the normal Latin letter K, not U+212A K KELVIN SIGN). When writing out the unit (not usually necessary), pluralize, e.g. 12 kelvins (see Kelvin#Orthography)
Energy cal In certain subject areas, calorie is convention­ally used alone; articles following this practice should specify on first use whether the use refers to the small calorie or to the kilocalorie (large calorie). Providing conversions to SI units (usually calories to joules or kilocalories to kilojoules) may also be useful. A kilocalorie (kcal) is 1000 calories. A calorie (small calorie) is the amount of energy required to heat 1 gram of water by 1 °C. A kilocalorie is also a kilogram calorie.
  • kilocalorie
  • large calorie
  • kilogram calorie
  • (not Calorie – can be ambiguous)
 kcal

Quantities of bytes and bits

Shortcut

In quantities of bits and bytes, the prefixes kilo- (symbol k or K), mega- (M), giga- (G), tera- (T), etc., are ambiguous in general usage. The meaning may be based on a decimal system (like the standard SI prefixes), meaning 10, 10, 10, 10, etc., or it may be based on a binary system, meaning 2, 2, 2, 2, etc. The binary meanings are more commonly used in relation to solid-state memory (such as RAM), while the decimal meanings are more common for data transmission rates, disk storage and in theoretical calculations in modern academic textbooks.

Prefixes for decimal and binary multiples
Decimal
Value SI
1000 10 k kilo
1000 10 M mega
1000 10 G giga
1000 10 T tera
1000 10 P peta
1000 10 E exa
1000 10 Z zetta
1000 10 Y yotta
1000 10 R ronna
1000 10 Q quetta
Binary
Value IEC JEDEC
1024 2 Ki kibi K kilo
1024 2 Mi mebi M mega
1024 2 Gi gibi G giga
1024 2 Ti tebi T tera
1024 2 Pi pebi —
1024 2 Ei exbi —
1024 2 Zi zebi —
1024 2 Yi yobi —
—
—

Follow these recommendations when using these prefixes in Misplaced Pages articles:

  • Following the SI standard, a lower-case k should be used for "kilo-" whenever it means 1000 in computing contexts, whereas a capital K should be used instead to indicate the binary prefix for 1024 according to JEDEC. If, under the exceptions detailed further below, the article otherwise uses IEC prefixes for binary units, use Ki instead.
  • Do not assume that the binary or decimal meaning of prefixes will be obvious to everyone. Explicitly specify the meaning of k and K as well as the primary meaning of M, G, T, etc. in an article ({{BDprefix}} is a convenient helper). Consistency within each article is desirable, but the need for consistency may be balanced with other considerations.
  • The definition most relevant to the article should be chosen as primary for that article, e.g. specify a binary definition in an article on RAM, decimal definition in an article on hard drives, bit rates, and a binary definition for Windows file sizes, despite files usually being stored on hard drives.
  • Where consistency is not possible, specify wherever there is a deviation from the primary definition.
  • Disambiguation should be shown in bytes or bits, with clear indication of whether in binary or decimal base. There is no preference in the way to indicate the number of bytes and bits, but the notation style should be consistent within an article. Acceptable examples include:
    • A 64 MB (64 × 1024-byte) video card and a 100 GB (100 × 1000-byte) hard drive
    • A 64 MB (64 × 2-byte) video card and a 100 GB (100 × 10-byte) hard drive
    • A 64 MB (67,108,864-byte) video card and a 100 GB (100,000,000,000-byte) hard drive
  • Avoid combinations with inconsistent form such as A 64 MB (67,108,864-byte) video card and a 100 GB (100 × 1000-byte) hard drive. Footnotes, such as those seen in Power Macintosh 5500, may be used for disambiguation.
  • Unless explicitly stated otherwise, one byte is eight bits (see Byte § History).
  • ShortcutThe IEC prefixes kibi- (symbol Ki), mebi- (Mi), gibi- (Gi), etc., are generally not to be used except:
    • when the majority of cited sources on the article topic use IEC prefixes;
    • in a direct quote using the IEC prefixes;
    • when explicitly discussing the IEC prefixes; or
    • in articles in which both types of prefix are used with neither clearly primary, or in which converting all quantities to one or the other type would be misleading or lose necessary precision, or declaring the actual meaning of a unit on each use would be impractical.

Currencies and monetary values

Shortcuts "WP:MONEY" and "WP:CURRENCY" redirect here. For the WikiProject focusing on articles about currencies, see Misplaced Pages:WikiProject Numismatics. "WP:$" and "WP:£" redirect here. For the policy on paid editing, see Misplaced Pages:Paid-contribution disclosure. For the humor page, see Help:Buying Misplaced Pages.

Choice of currency

  • In country-specific articles, such as Economy of Australia, use the currency of the subject country.
  • In non-country-specific articles, such as Wealth, use US dollars (US$123 on first use, generally $123 thereafter), euros (€123), or pounds sterling (£123).

Currency names

  • Do not capitalize the names or denominations of currencies, currency subdivisions, coins and banknotes: not a Five-Dollar bill, four Quarters, and one Penny total six Dollars one Cent but a five-dollar bill, four quarters, and one penny total six dollars one cent. Exception: where otherwise required, as at the start of a sentence or in such forms as Australian dollar.
  • To pluralize euro, use the standard English plurals (ten euros and fifty cents), not the invariant plurals used for European Union legislation and banknotes (ten euro and fifty cent). For the adjectival form, use a hyphenated singular (a two-euro pen and a ten-cent coin).
  • Link the first occurrence of lesser-known currencies (e.g. Mongolian tögrögs).

Currency symbols

  • In general, the first mention of a particular currency should use its full, unambiguous signifier (e.g. A$52), with subsequent references using just the appropriate symbol (e.g. $88), unless this would be unclear. Exceptions:
    • In an article referring to multiple currencies represented by the same symbol (e.g. the dollars of the US, Canada, Australia, New Zealand, and other countries – see Currency symbols § dollar variants) use the full signifier (e.g. US$ or A$, but not e.g. $US123 or $123 (US)) each time, except (possibly) where a particular context makes this both unnecessary and undesirable.
    • In articles entirely on US-related topics, all occurrences of the US dollar may be shortened ($34), unless this would be unclear.
    • For currencies that use a unit named the "pound":
      • Use the £ symbol (U+00A3 £ POUND SIGN) for unambiguous referrals to sterling, the United Kingdom's currency. Avoid the U+20A4 ₤ LIRA SIGN.
      • GBP, sterling's ISO 4217 code, should be used to disambiguate that currency from others. Avoid using stg. or GB£.
      • For currencies other than sterling, use the symbol or abbreviation conventionally employed for that currency, if any.
  • Link the first occurrence of lesser-known currency symbols (e.g. ₮)
  • If there is no common English abbreviation or symbol, follow the ISO 4217 standard. See also List of circulating currencies.
See also: Misplaced Pages:Manual of Style/Abbreviations § Unicode abbreviation ligatures

Currency formatting

  • A point (full stop or period, .) – never a comma – is used as the decimal marker ($6.57, not $6,57).
  • For the grouping of digits (e.g. £1,234,567) see § Grouping of digits, above.
  • Do not place a currency symbol after the accompanying numeric figures (e.g. 123$, 123£, 123€) unless that is the normal convention for that symbol when writing in English: smaller British coins include 1p, 2p, and 5p denominations.
  • Currency abbreviations preceding a numeric value are unspaced if they consist of a nonalphabetic symbol alone (£123 or €123), or end with a nonalphabetic symbol (R$123); but spaced (using {{nbsp}}) if completely alphabetic (R 123 or JOD 123).
  • Ranges should be expressed giving the currency signifier just once: $250–300, not $250–$300.
  • million and billion should be spelled out on first use, and (optionally) abbreviated M or bn (both unspaced) thereafter: She received £70 million and her son £10M; the school's share was $250–300 million, and the charity's $400–450M.
  • In general, a currency symbol should be accompanied by a numeric amount e.g. not He converted his US$ to A$ but He converted his US dollars to Australian dollars or He exchanged the US$100 note for Australian dollars.
    • Exceptions may occur in tables and infoboxes where space is limited e.g. Currencies accepted: US$, SFr, £, €. It may be appropriate to wikilink such uses, or add an explanatory note.

Currency conversions

  • Conversions of lesser-known currencies may be provided in terms of more familiar currencies – such as the US dollar, euro or pound sterling – using an appropriate rate (which is often not the current exchange rate). Conversions should be in parentheses after the original currency, along with the convert-to year; e.g. the grant in 2001 was 10,000,000 Swedish kronor ($1.4M, €970,000, or £850,000 as of 2009)
  • For obsolete currencies, provide an equivalent (formatted as a conversion) if possible, in the modern replacement currency (e.g. euros for amounts denominated in francs), or a US-dollar equivalent where there is no modern equivalent.
  • In some cases, it may be appropriate to provide a conversion accounting for inflation or deflation over time. See {{Inflation}} and {{Inflation-fn}}.
  • When converting among currencies or inflating/deflating, it is rarely appropriate to give the converted amount to more than three significant figures; typically, only two significant figures are justified: the grant in 2001 was 10,000,000 Swedish kronor ($1.4M, €970,000, or £850,000), not ($1,390,570, €971,673 or £848,646)

Common mathematical symbols

Shortcuts See also: Misplaced Pages:Manual of Style/Mathematics, Misplaced Pages:Manual of Style § Common mathematical symbols, and Help:Displaying a formula
  • The Insert menu below the editing window gives a more complete list of math symbols, and allows symbols to be inserted without the HTML encoding (e.g. &divide;) shown here.
  • Spaces are placed to left and right when a symbol is used with two operands (the sum 4 + 5), but no space is used when there is one operand (the value +5). Exception: spaces are usually omitted in inline fractions formed with /: 3/4 not 3 / 4.
  • The {{mvar}} (for single-letter variables) and {{math}} (for more complicated expressions) templates are available to display mathematical formulas in a manner distinct from surrounding text.
  • The {{nbsp}} and {{nowrap}} templates may be used to prevent awkward linebreaks.
Common mathematical symbols
Symbol name Example Markup Comments
Plus /
positive 		x + y {{math|''x'' + ''y''}}
+y {{math|+''y''}}
Minus /
negative 		x − y {{math|''x'' &minus; ''y''}} Do not use hyphens (-) or dashes ({{ndash}} or {{mdash}}).
−y {{math|&minus;''y''}}
Plus-minus /
minus-plus 		41.5 ± 0.3 41.5 &plusmn; 0.3
−(±a) = ∓a {{math|1=&minus;(&plusmn;''a'') = &#8723;''a''}}
Multiplication,
dot 		x ⋅ y {{math|''x'' &sdot; ''y''}} Do not use the letter x to indicate multiplication. However, an unspaced x may be used as a substitute for "by" in common terms such as 4x4.
Multiplication,
cross 		x × y {{math|''x'' &times; ''y''}}
Division, obelus x ÷ y {{math|''x'' &divide; ''y''}}
Equal / equals x = y {{math|1=''x'' = ''y''}} or
{{math|''x'' {{=}} ''y''}} 		Note the use of 1= or {{=}} to make the template parameters work correctly
Not equal x ≠ y {{math|''x'' &ne; ''y''}}
Approx. equal π ≈ 3.14 {{math|''&pi;'' &asymp; 3.14}}
Less than x < y {{math|''x'' &lt; ''y''}}
Less or equal x ≤ y {{math|''x'' &le; ''y''}}
Greater than x > y {{math|''x'' &gt; ''y''}}
Greater or equal x ≥ y {{math|''x'' &ge; ''y''}}

Geographical coordinates

Shortcuts
For draft guidance on, and examples of, coordinates for linear features, see Misplaced Pages:WikiProject Geographical coordinates/Linear.
Quick guide:
Quick how-to

To add 57°18′22″N 4°27′32″W / 57.30611°N 4.45889°W / 57.30611; -4.45889 to the top of an article, use {{Coord}}, thus:

{{Coord|57|18|22|N|4|27|32|W|display=title}}

These coordinates are in degrees, minutes, and seconds of arc.

"title" means that the coordinates will be displayed next to the article's title at the top of the page (in desktop view only; title coordinates do not display in mobile view) and before any other text or images. It also records the coordinates as the primary location of the page's subject in Misplaced Pages's geosearch API.

To add 44°06′45″N 87°54′47″W / 44.1124°N 87.9130°W / 44.1124; -87.9130 to the top of an article, use either

{{Coord|44.1124|N|87.9130|W|display=title}}

(which does not require minutes or seconds but does require the user to specify north/ south and east/west) or

{{Coord|44.1124|-87.9130|display=title}}

(in which the north and east are presumed by positive values while the south and west are negative ones). These coordinates are in decimal degrees.

  • Degrees, minutes and seconds, when used, must each be separated by a pipe ("|").
  • Map datum must be WGS84 if possible (except for off-Earth bodies).
  • Avoid excessive precision (0.0001° is <11 m, 1″ is <31 m).
  • Maintain consistency of decimal places or minutes/seconds between latitude and longitude.
  • Latitude (N/S) must appear before longitude (E/W).

Optional coordinate parameters follow the longitude and are separated by an underscore ("_"):

Other optional parameters are separated by a pipe ("|"):

  • display
    |display=inline (the default) to display in the body of the article only,
    |display=title to display at the top of the article only (in desktop view only; title coordinates do not display in mobile view), or
    |display=inline,title to display in both places.
  • name
    name=X to label the place on maps (default is PAGENAME)

Thus: {{Coord|44.1172|-87.9135|dim:30_region:US-WI_type:event

|display=inline,title|name=accident site}}

Use |display=title (or |display=inline,title) once per article, for the subject of the article, where appropriate.

Geographical coordinates on Earth should be entered using a template to standardise the format and to provide a link to maps of the coordinates. As long as the templates are adhered to, a robot performs the functions automatically.

First, obtain the coordinates. Avoid excessive precision.

The {{Coord}} template offers users a choice of display format through user styles, emits a Geo microformat, and is recognised (in the title position) by the "nearby" feature of Misplaced Pages's mobile apps and by external service providers such as Google Maps and Google Earth, and Yahoo. Infoboxes automatically emit {{Coord}}.

The following formats are available.

  • For degrees only (including decimal values): {{coord|dd|N/S|dd|E/W}}
  • For degrees/minutes: {{coord|dd|mm|N/S|dd|mm|E/W}}
  • For degrees/minutes/seconds: {{coord|dd|mm|ss|N/S|dd|mm|ss|E/W}}

where:

  • dd, mm, ss are the degrees, minutes and seconds, respectively;
  • N/S is either N for northern or S for southern latitudes;
  • E/W is either E for eastern or W for western longitudes;
  • negative values may be used in lieu of S and W to denote Southern and Western Hemispheres

For example:

For the city of Oslo, located at 59° 54′ 50″ N, 10° 45′ 8″ E:

{{coord|59|54|50|N|10|45|08|E}} – which becomes 59°54′50″N 10°45′08″E / 59.91389°N 10.75222°E / 59.91389; 10.75222

For a country, like Botswana, with no source on an exact geographic center, less precision is appropriate due to uncertainty:

{{coord|22|S|24|E}} – which becomes 22°S 24°E / 22°S 24°E / -22; 24

Higher levels of precision are obtained by using seconds:

{{coord|33|56|24|N|118|24|00|W}} – which becomes 33°56′24″N 118°24′00″W / 33.94000°N 118.40000°W / 33.94000; -118.40000

Coordinates can be entered as decimal values:

{{coord|33.94|S|118.40|W}} – which becomes 33°56′S 118°24′W / 33.94°S 118.40°W / -33.94; -118.40

Increasing or decreasing the number of decimal places controls the precision. Trailing zeros may be added as needed to give both values the same appearance.

Heathrow Airport, Amsterdam, Jan Mayen and Mount Baker are examples of articles that contain geographical coordinates.

Generally, the larger the object being mapped, the less precise the coordinates should be. For example, if just giving the location of a city, precision greater than degrees (°), minutes (′), seconds (″) is not needed, which suffice to locate, for example, the central administrative building. Specific buildings or other objects of similar size would justify precisions down to 10 meters or even one meter in some cases (1″ ~15 m to 30 m, 0.0001° ~5.6 m to 10 m).

The final field, following the E/W, is available for attributes such as type:, region:, or scale: (the codes are documented at Template:Coord/doc § Coordinate parameters).

When adding coordinates, please remove the {{coord missing}} tag from the article, if present (often at the top or bottom).

For more information, see the geographical coordinates WikiProject.

Templates other than {{coord}} should use the following variable names for coordinates: lat_d, lat_m, lat_s, lat_NS, long_d, long_m, long_s, long_EW.

See also

Notes

  1. See Arbitration Committee statements of principles in cases on style-related edit warring in June 2005, November 2005, and February 2006; and Misplaced Pages:General sanctions/Units in the United Kingdom.
  2. See also this July 2022 RfC.
  3. ^ For use in tables, infoboxes, references, etc. Only certain citation styles use abbreviated date formats. By default, Misplaced Pages does not abbreviate dates. Use a consistent citation style within any one article.
  4. All-numeric yyyy-mm-dd dates might be assumed to follow the ISO 8601 standard, which mandates the Gregorian calendar. Also, technically all years must have (only) four digits, but Misplaced Pages is unlikely to need to format a date beyond the year 9999 anytime soon.
  5. The routine linking of dates is deprecated. This change was made August 24, 2008, on the basis of this archived discussion. It was ratified in two December 2008 RfCs: Misplaced Pages:Manual of Style/Dates and numbers/Three proposals for change to MOSNUM and Misplaced Pages:Manual of Style/Dates and numbers/Date Linking RFC.
  6. For consensus discussion on abbreviated date formats like "Sep 2", see Misplaced Pages talk:Manual of Style/Archive 151 § RFC: Month abbreviations
  7. These formats cannot, in general, be distinguished on sight, because there are usages in which 05-03-1991 represents March 5, and other usages in which it represents May 3. According to a prehistoric discussion of Misplaced Pages date formats:

    Some years ago an American student I knew at university went into a panic when she received a note informing her that her exams were scheduled to start on 03-05-1991. She went into a severe weekend of cramming (studying for 18+ hours per day), until she was almost hospitalised from exhaustion. Only then did she realise that her exams didn't start on the 5th of March – two weeks from the date she got the notice – but the 3rd of May.

    In contrast, there is no common usage in which 1991-05-03 represents anything other than May 3.

  8. ^ Body in this context means the main prose of the article, as distinguished from reference citations, tabular data, infoboxes, navigation templates, and metadata such as hatnote templates, etc. Other parts of the Manual of Style may use body to mean 'the bulk of the article after the lead section', but that is not the meaning here. Misplaced Pages's article leads are not written in a different prose style from the material following them.
  9. The calendar practices of Oxford Dictionary of National Biography and Encyclopædia Britannica can be inferred by looking up the birth and death dates of famous, well-documented individuals.
  10. A change from a preference for two digits, to a preference for four digits, on the right side of year–year ranges was implemented in July 2016 per this RFC.
  11. Some precomposed fractions may not work with screen readers, and not all fractions are available precomposed.
  12. These three characters are in ISO/IEC 8859-1 and work in screen readers.
  13. The number in parentheses in a construction like 1.604(48) × 10 J is the numerical value of the standard uncertainty referred to the corresponding last digits of the quoted result.
  14. The prefixes 0x for hexadecimal and 0b for binary have widespread support in systems programming languages including C, C++, Python, Rust and Swift.
  15. One such situation is with Unicode codepoints, which use U+; U+26A7, not 0x26A7.
  16. If there is disagreement about the primary units used in a UK-related article, discuss the matter on the article talk-page or at Misplaced Pages talk:Manual of Style/Dates and numbers (WT:MOSNUM). If consensus cannot be reached, refer to historically stable versions of the article and retain the units used in these as the primary units. Also note the style guides of British publications (e.g. The Times, under "Metric").
  17. These definitions are consistent with all units of measure mentioned in the SI Brochure and with all units of measure catalogued in EU directive 80/181/EEC.
  18. Misplaced Pages follows common practice regarding bytes and other data traditionally quantified using binary prefixes (e.g. mega- and kilo-, meaning 2 and 2 respectively) and their unit symbols (e.g. MB and KB) for RAM and decimal prefixes for most other uses. Despite the IEC's 1998 international standard creating several new binary prefixes (e.g. mebi-, kibi-, etc.) to distinguish the meaning of the decimal SI prefixes (e.g. mega- and kilo-, meaning 10 and 10 respectively) from the binary ones, and the subsequent incorporation of these IEC prefixes into the IEC 80000-13, consensus on Misplaced Pages in computing-related contexts favours the retention of the more familiar but ambiguous units KB, MB, GB, TB, PB, EB, etc. over use of unambiguous IEC binary prefixes. For detailed discussion, see WT:Manual of Style (dates and numbers)/Archive/Complete rewrite of Units of Measurements (June 2008).
  19. Whether 00A3 is displayed with one or two bars is typeface (font) dependent.
  20. See also this February 2023 RfC.

References

  1. Garraty, John A.; Carnes, Mark C., eds. (1999). "Editorial note". American National Biography. Oxford University Press. pp. xxi–xxii.
  2. Coordinated Universal Time (UTC) (PDF). Bureau International des Poids et Mesures. June 2, 2009. p. 3. CCTF/09-32. Retrieved October 5, 2022. This coordination began on January 1, 1960, and the resulting time scale began to be called informally 'Coordinated Universal Time.' 
  3. "Fundamental Physical Constants: Standard Uncertainty and Relative Standard Uncertainty". The NIST Reference on Constants, Units, and Uncertainty. US National Institute of Standards and Technology. June 25, 2015. Retrieved December 12, 2017.
  4. ^ "Chapter 4: Non-SI units that are accepted for use with the SI". SI Brochure: The International System of Units (SI) (PDF) (9th ed.). Bureau International des Poids et Mesures. 2019. Retrieved 2020-09-24. Table 8, p 145, gives additional guidance on non-SI units.
  5. "Council Directive of 20 December 1979 on the approximation of the laws of the Member States relating to units of measurement". Eur-Lex.Europa.eu. European Union. 2017 . 80/181/EEC (Document 01980L0181-20090527). Retrieved December 12, 2017.
  6. Wilkins, G. A. (1989). "5.14 Time and angle". IAU Style Manual (PDF). International Astronomical Union. p. S23. Retrieved 12 December 2017.
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convert many units (see: list)
cvt abbreviated {{convert}}
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decdeg degrees, minutes, and seconds to decimal degrees
deg2dms decimal degrees to degrees, minutes, and seconds
deg2hms decimal degrees to hour angle (in hours, minutes, and seconds)
hms2deg hour angle (in hours, minutes, and seconds) to decimal degrees
inflation calculate inflation of Consumer Price Index-related prices
pop density population density in an area
track gauge railway track gauges
Notation and formatting
bigmath bigger font to match TeX \displaystyle (standalone formulas only)
bra–ket notation
ceil, floor calculations :mw:Help:#expr; formatting indicators ⌈3.14⌉, ⌊3.14⌋ (no calculation performed)
fraction slant fractions 3⁄5 (not for maths/science articles; use standing or upright fractions {{sfrac}} instead)
intmath integral symbols
  • langle
  • rangle
  • angbr
    		•  angular brackets
  • ldelim
  • rdelim
    		•  multiline delimiters (2–5 lines inclusive)
    abs absolute values (paired vertical lines)
    math short text-based formulas
    mathcal calligraphic font; alternative to LaTeX \mathcal{...}
    mvar individual italicized maths variables in normal text
  • overline
  • underline
    		•  a line set above/below a sequence of characters
    overarc an arc set above a sequence of characters
  • overset
  • underset
    		•  arbitrary characters/diacritics set above/below one another
    pars parentheses that can be resized (∑)
    sfrac "standing" or upright fractions ⁠3/5⁠ (use in maths/science articles instead of{{fraction}})
  • sub
  • sup
  • su
    		•  subscripts and superscripts
    tmath Wrap TeX in <math> tags
    tombstone symbol indicating the end of a proof
    val measurement values, uncertainties and units
    vec various overarrows, underarrows, etc.
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