Centimetre
Unit of length
A centimetre (International spelling) or centimeter (American English), with SI symbol cm, is a 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 1/100. Equivalently, there are 100 centimetres in 1 metre. The centimetre is the base unit of length in the now deprecated centimetre-gram-second (CGS) system of units.
Though for many physical quantities, SI prefixes for factors of 103, 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. A centimetre is approximately the width of the fingernail of an average adult person.
01Equivalence to other units of length
| 1 centimetre | = 10 millimetres |
| = 0.01 metres | |
| = 0.3937 inches (There are exactly 2.54 centimetres in one inch.) | |
| = 0.0109 yards |
One millilitre is defined as one cubic centimetre, under the SI system of units.
02Other 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
- in the CGS system, the centimetre is used to measure capacitance, where 1 cm of capacitance = 1.113×10−12 farads
- in maps, centimetres are used to make conversions from map scale to real world scale (kilometres)
- to represent second moment of areas (cm4)
- as the inverse of the 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−1.
03Unicode symbols
For the purposes of compatibility with Chinese, Japanese and Korean (CJK) characters, Unicode has symbols for:
- centimetre, U+339D ㎝ SQUARE CM
- square centimetre, U+33A0 ㎠ SQUARE CM SQUARED
- cubic centimetre, U+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.
Sources and credits
This article is adapted from the Wikipedia article “Centimetre”, written by its contributors and licensed under CC BY-SA 4.0. Fathomly has changed the layout, removed citation markers, navigation and maintenance notices, and adjusted punctuation. This adapted version is shared under the same license. For references, see the original article.
Images, from Wikimedia Commons:
- CarpentersRule.png by Unknown author, Public domain
- EM Spectrum Properties edit.svg by Inductiveload, NASA, CC BY-SA 3.0
Fathomly is not affiliated with or endorsed by the Wikimedia Foundation. Spotted a problem? Tell us.
