This
guideline is a part of the English Wikipedia's
Manual of Style. It is a generally accepted standard that editors should attempt to follow, though it is best treated with
common sense, and
occasional exceptions may apply. Any substantive edit to this page should reflect
consensus. When in doubt, discuss first on the
talk page. |
Manual of Style (MoS) |
---|
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 Wikipedia 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. [a] 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.
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 [bracketed interpolation], article text, or footnotes.
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
) or {{
nowrap}}
may be appropriate are described.
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 Terms likely to go out of date include best known for, holds the record for, etc. [b] For current and future events, use phrases such as as of July 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.
General use | Only in limited situations where brevity is helpful [c] |
Comments |
---|---|---|
2 September 2001 | 2 Sep 2001 | A comma doesn't follow the year unless otherwise required by context:
|
September 2, 2001 | Sep 2, 2001 | A comma follows the year unless
other punctuation obviates it:
|
2 September | 2 Sep | Omit year only where there is no risk of ambiguity:
|
September 2 | Sep 2 | |
No equivalent for general use | 2001-09-02 | Use yyyy-mm-dd format only with Gregorian dates from 1583 onward. [d] |
September 2001 | Sep 2001 |
{{
dts|Nov 1, 2008}}
.
Unacceptable | Corrected | Comments |
---|---|---|
Sep. 2 | Sep 2 [c] | Do not add a full stop (period) to an abbreviated month or to the day-of-month. [f] |
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 [c] | ... 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. [g] | |
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). |
{{
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, .)For any given article, the choice of date format and the choice of national variety of English (see Wikipedia:Manual of Style § Strong national ties to a topic) are independent issues.
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.
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, [1] Oxford Dictionary of National Biography, and Encyclopædia Britannica. [i]
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.
–
, –
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{{
ndash}}1882
or 1881–1882
{{
snd}}
) is used. For example:
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. 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.
{{
Age}}
template can keep ages current in infoboxes and so on:
{{age|1989|7|23}}
returns: 34{{age|1989|7|23}}-year-old
returns: 34-year-old{{age|1989|7|23}} years old
returns: 34 years old{{
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.:
c.
should appear before each date (the two-argument form of {{
circa}}
does this):
[[Floruit|fl.]]
, or {{
fl.}}
may be used:
{{
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.{{snd}}
).
1896{{snd}}after 1954
, 470{{snd}}{{c.|540}}
, {{c.|470}}{{snd}}540
, {{c.|470|540}}
.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.).
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.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; [2] 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.
The sequence of numbered years in dates runs ... 2 BC, 1 BC, 1 AD, 2 AD ...; there is no " year zero".
Generally, in article text:
Notes and exceptions:
Other numbers
21{{nbsp}}million
[[crore]]
, 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.{{
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.
Like 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.
, number ranges and page ranges should state the full value of both the beginning and end of the range, separated by anSport scores, vote tallies, or other presentations that juxtapose two opposing quantities use an unspaced en dash:
To avoid potential line breaks, use {{
nowrap}}
around the entire score construction, or use {{
nbnd}}
instead of {{
ndash}}
.
{{frac|1|4}} 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.{{frac|9|3|4}}
)). In any case the integer and fractional parts should be consistent (not Platform nine and 3⁄4).{{
frac}}
is discouraged; instead use one of these styles:
a 3.5 : 1 ratio
))..
) as the
decimal separator, never a comma: 6.57, not 6,57.14.31{{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.
{{
formatnum:}}
produces this formatting.{{
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. 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.%
is generally preferred. Omit space (3%, not 3 %), and avoid mixed forms such as three %.%
symbol or the word(s) percent (American English) or per cent (British English): 10 percent; ten percent; 4.5 per cent.{{e|7}}
)Markup: {{
val}}
and {{
e}}
may be used to format exponential notation.
{{
+-}}
, {{
su}}
, and {{
val}}
may be used to format uncertainties.{{
undue precision}}
template may be added to figures appearing to be overprecise.0x
for hexadecimal and 0b
for binary,
[n] unless there is a strong reason to use some other notation.
[o] Explain these prefixes in the article's introduction or on first use.{{
base}}
: 1379, 2013. Markup: {{base|137|9}}
, {{base|201|3}}
There are multiple ways to display mathematical formulae, covered in detail at
Wikipedia: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.
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:
Special considerations:
{{
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.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.
{{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}}
).{{
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.{{
Units attention}}
may be added to articles needing general attention regarding choice of units and unit conversions.{{
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).×
or ×
) or the word by
.
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. [q] | 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 [4] or this Manual of Style. |
|
| |
|
|||
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. |
|
||
Use a non-breaking space ({{
nbsp}} or ) between a number and a unit symbol, or use {{
nowrap}} ...
|
29 kg (markup: 29 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 ... |
|
||
... but a non-breaking space (never hyphen) separates a value and unit symbol. |
|
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 ins | |
Powers
|
Format exponents using <sup>, not special characters. | km2 (markup: km<sup>2</sup> )
|
km² ( km² )
|
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. |
|
|
Indicate a product of unit symbols with &
sdot; or &
nbsp; .
|
|
||
Exception: In some topic areas, such as power engineering, certain products take neither space nor ⋅ . 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 −1, −2, etc.
|
|
| |
|
| ||
To pluralize a ratio of unit names, pluralize only the numerator unit. (Unit symbols are never pluralized.) |
|
||
Some of the special forms used in the imperial and US customary systems are shown here ... |
|
||
... but only the slash or negative exponent notations are used with SI (and other metric) units. |
|
gsm | |
|
kph | ||
Prefixes
|
Prefixes should not be separated by a space or hyphen. | kilopascal |
|
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. |
|
1 hectometre | |
Do not use M for 103, MM for 106, or B for 109 (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 ... |
|
|
|
|||
... and in expressing time durations ... |
| ||
... but are not used with metric units. |
|
1 m 33 cm |
Note to table:
Group
|
Unit name | Unit symbol | Comment |
---|---|---|---|
Length, speed
|
|
|
Do not use ′ (′), ″ (″), 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. | |
|
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. | ||
|
m | ||
micron | μm (not μ) | Markup: μm 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. | |
|
|
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
|
|
cm3 | Markup: cm<sup>3</sup>
|
cc | Non-SI abbreviation used for certain engine displacements. Link to Cubic centimetre on first use. | ||
|
|
| |
cubic foot | cu ft (not cf) | Write five million cubic feet, 5,000,000 cu ft, or 5×106 cu ft, not 5 MCF. | |
cubic foot per second | cu ft/s (not cfs) | ||
|
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. | |
|
ml or mL | Derivative units of the litre may use l (lowercase "el"). | |
Mass, weight, force, density, pressure
|
|
|
Not gramme, kilogramme |
|
Spell out in full. | ||
|
t (not mt, MT, or Mt) | ||
pound per square inch | psi | ||
|
|
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. | |
|
| ||
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
|
|
|
Do not use ′ (′), ″ (″), 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 | |||
Information, data
|
bit | bit (not b or B) | baud (Bd). | Do not confuse bit/second or byte/second with
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 12°{{
nbsp}}C |
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. |
|
kcal |
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 103, 106, 109, 1012, etc., or it may be based on a binary system, meaning 210, 220, 230, 240, 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.
Follow these recommendations when using these prefixes in Wikipedia articles:
{{
BDprefix}}
is a convenient helper). Consistency within each article is desirable, but the need for consistency may be balanced with other considerations.Choice of currency
Currency names
Currency symbols
Currency formatting
.
) – never a comma – is used as the decimal marker ($6.57, not $6,57).Currency conversions
÷
) shown here./
: 3/4 not 3 / 4.{{
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.{{
nbsp}}
and {{
nowrap}}
templates may be used to prevent awkward linebreaks.Symbol name | Example | Markup | Comments |
---|---|---|---|
Plus / positive |
x + y | {{math|''x'' + ''y''}}
|
|
+y | {{math|+''y''}}
| ||
Minus / negative |
x − y | {{math|''x'' − ''y''}}
|
Do not use hyphens (- ) or dashes ({{
ndash}} or {{
mdash}} ).
|
−y | {{math|−''y''}}
| ||
Plus-minus / minus-plus |
41.5 ± 0.3 | 41.5 ± 0.3
|
|
−(±a) = ∓a | {{math|1=−(±''a'') = ∓''a''}}
| ||
Multiplication, dot |
x ⋅ y | {{math|''x'' ⋅ ''y''}}
| |
Multiplication, cross |
x × y | {{math|''x'' × ''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. |
Division, obelus | x ÷ y | {{math|''x'' ÷ ''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'' ≠ ''y''}}
|
|
Approx. equal | π ≈ 3.14 | {{math|''π'' ≈ 3.14}}
| |
Less than | x < y | {{math|''x'' < ''y''}}
| |
Less or equal | x ≤ y | {{math|''x'' ≤ ''y''}}
| |
Greater than | x > y | {{math|''x'' > ''y''}}
| |
Greater or equal | x ≥ y | {{math|''x'' ≥ ''y''}}
|
To add 57°18′22″N 4°27′32″W / 57.30611°N 4.45889°W 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 Wikipedia's geosearch API.
To add 44°06′45″N 87°54′47″W / 44.1124°N 87.9130°W 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.
Optional coordinate parameters follow the longitude and are separated by
an underscore ("_"):
dim:
N (viewing diameter in metres)region:
R (
ISO 3166-1 alpha-2 or
ISO 3166-2 code)type:
T (landmark
or city(30,000)
, for example)Other optional parameters are separated by
a pipe ("|"):
|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=
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 Wikipedia'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.
{{coord|dd|N/S|dd|E/W}}
{{coord|dd|mm|N/S|dd|mm|E/W}}
{{coord|dd|mm|ss|N/S|dd|mm|ss|E/W}}
where:
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°EFor 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°EHigher 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°WCoordinates 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°WIncreasing 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:
.
When adding coordinates, please remove the {{
coord missing}}
tag from the article, if present (often at the top or bottom).
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.
0x
for hexadecimal and 0b
for binary have widespread support in systems programming languages including
C,
C++,
Rust and
Swift.
U+
; U+26A7, not 0x26A7.
This coordination began on January 1, 1960, and the resulting time scale began to be called informally 'Coordinated Universal Time.'
This
guideline is a part of the English Wikipedia's
Manual of Style. It is a generally accepted standard that editors should attempt to follow, though it is best treated with
common sense, and
occasional exceptions may apply. Any substantive edit to this page should reflect
consensus. When in doubt, discuss first on the
talk page. |
Manual of Style (MoS) |
---|
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 Wikipedia 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. [a] 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.
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 [bracketed interpolation], article text, or footnotes.
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
) or {{
nowrap}}
may be appropriate are described.
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. [b] For current and future events, use phrases such as as of July 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.
General use | Only in limited situations where brevity is helpful [c] |
Comments |
---|---|---|
2 September 2001 | 2 Sep 2001 | A comma doesn't follow the year unless otherwise required by context:
|
September 2, 2001 | Sep 2, 2001 | A comma follows the year unless
other punctuation obviates it:
|
2 September | 2 Sep | Omit year only where there is no risk of ambiguity:
|
September 2 | Sep 2 | |
No equivalent for general use | 2001-09-02 | Use yyyy-mm-dd format only with Gregorian dates from 1583 onward. [d] |
September 2001 | Sep 2001 |
{{
dts|Nov 1, 2008}}
.
Unacceptable | Corrected | Comments |
---|---|---|
Sep. 2 | Sep 2 [c] | Do not add a full stop (period) to an abbreviated month or to the day-of-month. [f] |
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 [c] | ... 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. [g] | |
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). |
{{
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, .)For any given article, the choice of date format and the choice of national variety of English (see Wikipedia:Manual of Style § Strong national ties to a topic) are independent issues.
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.
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, [1] Oxford Dictionary of National Biography, and Encyclopædia Britannica. [i]
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.
–
, –
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{{
ndash}}1882
or 1881–1882
{{
snd}}
) is used. For example:
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. 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.
{{
Age}}
template can keep ages current in infoboxes and so on:
{{age|1989|7|23}}
returns: 34{{age|1989|7|23}}-year-old
returns: 34-year-old{{age|1989|7|23}} years old
returns: 34 years old{{
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.:
c.
should appear before each date (the two-argument form of {{
circa}}
does this):
[[Floruit|fl.]]
, or {{
fl.}}
may be used:
{{
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.{{snd}}
).
1896{{snd}}after 1954
, 470{{snd}}{{c.|540}}
, {{c.|470}}{{snd}}540
, {{c.|470|540}}
.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.).
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.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; [2] 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.
The sequence of numbered years in dates runs ... 2 BC, 1 BC, 1 AD, 2 AD ...; there is no " year zero".
Generally, in article text:
Notes and exceptions:
Other numbers
21{{nbsp}}million
[[crore]]
, 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.{{
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.
Like 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.
, number ranges and page ranges should state the full value of both the beginning and end of the range, separated by anSport scores, vote tallies, or other presentations that juxtapose two opposing quantities use an unspaced en dash:
To avoid potential line breaks, use {{
nowrap}}
around the entire score construction, or use {{
nbnd}}
instead of {{
ndash}}
.
{{frac|1|4}} 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.{{frac|9|3|4}}
)). In any case the integer and fractional parts should be consistent (not Platform nine and 3⁄4).{{
frac}}
is discouraged; instead use one of these styles:
a 3.5 : 1 ratio
))..
) as the
decimal separator, never a comma: 6.57, not 6,57.14.31{{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.
{{
formatnum:}}
produces this formatting.{{
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. 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.%
is generally preferred. Omit space (3%, not 3 %), and avoid mixed forms such as three %.%
symbol or the word(s) percent (American English) or per cent (British English): 10 percent; ten percent; 4.5 per cent.{{e|7}}
)Markup: {{
val}}
and {{
e}}
may be used to format exponential notation.
{{
+-}}
, {{
su}}
, and {{
val}}
may be used to format uncertainties.{{
undue precision}}
template may be added to figures appearing to be overprecise.0x
for hexadecimal and 0b
for binary,
[n] unless there is a strong reason to use some other notation.
[o] Explain these prefixes in the article's introduction or on first use.{{
base}}
: 1379, 2013. Markup: {{base|137|9}}
, {{base|201|3}}
There are multiple ways to display mathematical formulae, covered in detail at
Wikipedia: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.
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:
Special considerations:
{{
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.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.
{{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}}
).{{
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.{{
Units attention}}
may be added to articles needing general attention regarding choice of units and unit conversions.{{
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).×
or ×
) or the word by
.
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. [q] | 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 [4] or this Manual of Style. |
|
| |
|
|||
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. |
|
||
Use a non-breaking space ({{
nbsp}} or ) between a number and a unit symbol, or use {{
nowrap}} ...
|
29 kg (markup: 29 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 ... |
|
||
... but a non-breaking space (never hyphen) separates a value and unit symbol. |
|
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 ins | |
Powers
|
Format exponents using <sup>, not special characters. | km2 (markup: km<sup>2</sup> )
|
km² ( km² )
|
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. |
|
|
Indicate a product of unit symbols with &
sdot; or &
nbsp; .
|
|
||
Exception: In some topic areas, such as power engineering, certain products take neither space nor ⋅ . 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 −1, −2, etc.
|
|
| |
|
| ||
To pluralize a ratio of unit names, pluralize only the numerator unit. (Unit symbols are never pluralized.) |
|
||
Some of the special forms used in the imperial and US customary systems are shown here ... |
|
||
... but only the slash or negative exponent notations are used with SI (and other metric) units. |
|
gsm | |
|
kph | ||
Prefixes
|
Prefixes should not be separated by a space or hyphen. | kilopascal |
|
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. |
|
1 hectometre | |
Do not use M for 103, MM for 106, or B for 109 (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 ... |
|
|
|
|||
... and in expressing time durations ... |
| ||
... but are not used with metric units. |
|
1 m 33 cm |
Note to table:
Group
|
Unit name | Unit symbol | Comment |
---|---|---|---|
Length, speed
|
|
|
Do not use ′ (′), ″ (″), 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. | |
|
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. | ||
|
m | ||
micron | μm (not μ) | Markup: μm 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. | |
|
|
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
|
|
cm3 | Markup: cm<sup>3</sup>
|
cc | Non-SI abbreviation used for certain engine displacements. Link to Cubic centimetre on first use. | ||
|
|
| |
cubic foot | cu ft (not cf) | Write five million cubic feet, 5,000,000 cu ft, or 5×106 cu ft, not 5 MCF. | |
cubic foot per second | cu ft/s (not cfs) | ||
|
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. | |
|
ml or mL | Derivative units of the litre may use l (lowercase "el"). | |
Mass, weight, force, density, pressure
|
|
|
Not gramme, kilogramme |
|
Spell out in full. | ||
|
t (not mt, MT, or Mt) | ||
pound per square inch | psi | ||
|
|
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. | |
|
| ||
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
|
|
|
Do not use ′ (′), ″ (″), 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 | |||
Information, data
|
bit | bit (not b or B) | baud (Bd). | Do not confuse bit/second or byte/second with
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 12°{{
nbsp}}C |
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. |
|
kcal |
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 103, 106, 109, 1012, etc., or it may be based on a binary system, meaning 210, 220, 230, 240, 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.
Follow these recommendations when using these prefixes in Wikipedia articles:
{{
BDprefix}}
is a convenient helper). Consistency within each article is desirable, but the need for consistency may be balanced with other considerations.Choice of currency
Currency names
Currency symbols
Currency formatting
.
) – never a comma – is used as the decimal marker ($6.57, not $6,57).Currency conversions
÷
) shown here./
: 3/4 not 3 / 4.{{
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.{{
nbsp}}
and {{
nowrap}}
templates may be used to prevent awkward linebreaks.Symbol name | Example | Markup | Comments |
---|---|---|---|
Plus / positive |
x + y | {{math|''x'' + ''y''}}
|
|
+y | {{math|+''y''}}
| ||
Minus / negative |
x − y | {{math|''x'' − ''y''}}
|
Do not use hyphens (- ) or dashes ({{
ndash}} or {{
mdash}} ).
|
−y | {{math|−''y''}}
| ||
Plus-minus / minus-plus |
41.5 ± 0.3 | 41.5 ± 0.3
|
|
−(±a) = ∓a | {{math|1=−(±''a'') = ∓''a''}}
| ||
Multiplication, dot |
x ⋅ y | {{math|''x'' ⋅ ''y''}}
| |
Multiplication, cross |
x × y | {{math|''x'' × ''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. |
Division, obelus | x ÷ y | {{math|''x'' ÷ ''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'' ≠ ''y''}}
|
|
Approx. equal | π ≈ 3.14 | {{math|''π'' ≈ 3.14}}
| |
Less than | x < y | {{math|''x'' < ''y''}}
| |
Less or equal | x ≤ y | {{math|''x'' ≤ ''y''}}
| |
Greater than | x > y | {{math|''x'' > ''y''}}
| |
Greater or equal | x ≥ y | {{math|''x'' ≥ ''y''}}
|
To add 57°18′22″N 4°27′32″W / 57.30611°N 4.45889°W 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 Wikipedia's geosearch API.
To add 44°06′45″N 87°54′47″W / 44.1124°N 87.9130°W 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.
Optional coordinate parameters follow the longitude and are separated by
an underscore ("_"):
dim:
N (viewing diameter in metres)region:
R (
ISO 3166-1 alpha-2 or
ISO 3166-2 code)type:
T (landmark
or city(30,000)
, for example)Other optional parameters are separated by
a pipe ("|"):
|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=
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 Wikipedia'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.
{{coord|dd|N/S|dd|E/W}}
{{coord|dd|mm|N/S|dd|mm|E/W}}
{{coord|dd|mm|ss|N/S|dd|mm|ss|E/W}}
where:
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°EFor 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°EHigher 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°WCoordinates 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°WIncreasing 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:
.
When adding coordinates, please remove the {{
coord missing}}
tag from the article, if present (often at the top or bottom).
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.
0x
for hexadecimal and 0b
for binary have widespread support in systems programming languages including
C,
C++,
Rust and
Swift.
U+
; U+26A7, not 0x26A7.
This coordination began on January 1, 1960, and the resulting time scale began to be called informally 'Coordinated Universal Time.'