Editing Centimetre

{{short description|Unit of length}}
{{Use British English |date=February 2023}}

{{Infobox unit
| name     = centimetre
| image    = [[Image:CarpentersRule.png|frameless]]
| caption  = A carpenter's [[ruler]] with centimetre divisions
| symbol   = cm
| standard = [[SI]]
| quantity = [[length]]
| units1   = [[millimetres]]
| inunits1 = 10&nbsp;[[millimetre|mm]]
| units2   = [[Imperial unit|imperial]] & [[United States customary units|US]] system
| inunits2 = ~{{convert|1|cm|in|4|disp=out|lk=out}} 
}}
{{Wiktionary|centimetre}}
{{broader|metre}}

[[file:EM Spectrum Properties edit.svg|thumb|upright=1.35|Different lengths as in respect to the [[electromagnetic spectrum]], measured by the metre and its derived scales. The [[microwave]] is in-between 1 meter to 1 millimeter.]]

A '''centimetre''' (International spelling) or '''centimeter''' ([[American English]]), with SI symbol '''cm''', is a [[Units of measurement|unit]] of [[length]] in the [[International System of Units]] (SI) equal to one hundredth of a [[metre]], ''centi-'' being the [[SI prefix]] for a factor of {{sfrac|100}}.<ref>{{cite web |url=http://www.bipm.org/en/publications/si-brochure/chapter3.html |title=Decimal multiples and submultiples of SI units |publisher=Bureau International des Poids et Mesures |year=2014 |access-date=5 July 2015}}</ref> Equivalently, there are 100 centimetres in 1 metre. The centimetre was the base unit of length in the now [[deprecated]] [[Centimetre–gram–second system of units|centimetre–gram–second]] (CGS) system of units.

Though for many physical quantities, [[SI prefix]]es for factors of 10<sup>3</sup>—like ''milli-'' and ''kilo-''—are often preferred by technicians, the centimetre remains a practical unit of length for many everyday measurements; for instance, [[human height]] is commonly measured in centimetres.<ref>{{cite web|title=Using the BMI-for-Age Growth Charts |url=https://www.cdc.gov/nccdphp/dnpa/growthcharts/training/modules/module1/text/page6bmetric.htm |website=cdc.gov |publisher=[[Centers for Disease Control]] |access-date=5 July 2014 |url-status=dead |archive-url=https://web.archive.org/web/20140130012800/http://www.cdc.gov/nccdphp/dnpa/growthcharts/training/modules/module1/text/page6bmetric.htm |archive-date=30 January 2014 |df=dmy }}</ref><ref>{{cite book|author=Price, Beth|title=MathsWorld Year 8 VELS Edition|date=2009|publisher=[[Macmillan Publishers|MacMillan]]|location=Australia|page=626|url=https://books.google.com/books?id=t2veDRPjMggC|display-authors=etal|isbn=978-0-7329-9251-4}}</ref> A centimetre is approximately the width of the fingernail of an average adult person.

==Equivalence to other units of length==

{|
|-
|rowspan=4 valign=top|{{calculator|id=cm|type=number|size=4|default=1}} centimetre
|= {{calculator|id=mm|type=plain|default=10|formula=cm*10|NaN-text=0}} [[millimetre]]s
|-
|= {{calculator|id=m|type=plain|default=0.01|formula=cm/100|NaN-text=0}} metres 
|-
|= {{calculator|id=in|type=plain|default=0.3937|formula=cm/2.54|NaN-text=0|decimals=4}} [[inch]]es (There are ''exactly'' 2.54 centimetres in one inch.)
|}

One [[litre|millilitre]] is defined as one cubic centimetre, under the [[SI]] system of units.

==Other uses==
In addition to its use in the measurement of [[length]], the centimetre is used:
* sometimes, to report the level of rainfall as measured by a [[rain gauge]]<ref>{{Cite web|url=https://www.weathershack.com/static/ed-rain-measurement.html|title=Rain Measurement|website=www.weathershack.com}}</ref>
* in the [[Centimetre gram second system of units|CGS system]], the centimetre is used to measure [[capacitance]], where 1&nbsp;cm of capacitance = {{val|1.113|e=-12}} [[farad]]s<ref>{{Cite web|url=https://scienceworld.wolfram.com/physics/Capacitance.html|title=Capacitance -- from Eric Weisstein's World of Physics|first=Eric W.|last=Weisstein|website=scienceworld.wolfram.com}}</ref>
* in  maps, centimetres are used to make conversions from map scale to real world scale (kilometres)
* to represent second moment of areas (cm<sup>4</sup>)
* as the inverse of the [[kayser (unit)|Kayser]], a CGS unit, and thus a non-SI metric unit of [[wavenumber]]:  1 kayser = 1 wave per centimetre; or, more generally, (wavenumber in kaysers) = 1/([[wavelength]] in centimetres). The SI unit of wavenumber is the inverse metre, m<sup>−1</sup>.

==Unicode symbols==
For the purposes of compatibility with [[Chinese language|Chinese]], [[Japanese language|Japanese]] and [[Korea]]n ([[CJK]]) characters, [[Unicode]] has symbols for:<ref>[https://www.unicode.org/charts/PDF/U3300.pdf CJK Compatibility excerpt] from The Unicode Standard, Version 10.0.</ref>
* centimetre – {{unichar|339D|SQUARE CM}}
* square centimetre – {{unichar|33A0|SQUARE CM SQUARED}}
* cubic centimetre – {{unichar|33A4|SQUARE CM CUBED}}

These characters are each equal in size to one Chinese character and are typically used only with East Asian, fixed-width [[CJK]] fonts.

==See also==
*[[Conversion of units]]
*[[Orders of magnitude (length)]]
*[[Reciprocal length]]

==References==
{{reflist}}

==External links==
* [https://stylespree.com/pages/cm-to-inch-converter CM to Inch Converter]

{{SI units of length}}
{{CGS units}}

{{Authority control}}

[[Category:Metre]]
[[Category:Orders of magnitude (length)|-02]]
[[Category:Centimetre–gram–second system of units]]
[[Category:SI units]]
[[Category:100 (number)]]