330px, Different lengths as in respect to the , measured by the Metre and its deriveds scales. The Microwave">Electromagnetic spectrum, measured by the Metre and its deriveds scales. The Microwave are in-between 1 meter to 1 millimeter.
A centimetre (international spelling) or centimeter (American spelling) (SI symbol cm) is a Units of measurement, unit of
length
Length is a measure of distance. In the International System of Quantities, length is a quantity with dimension distance. In most systems of measurement a base unit for length is chosen, from which all other units are derived. In the Inte ...
in the International System of Units (SI), equal to one hundredth of a
metre
The metre ( British spelling) or meter ( American spelling; see spelling differences) (from the French unit , from the Greek noun , "measure"), symbol m, is the primary unit of length in the International System of Units (SI), though its p ...
, ''centi'' being the
SI prefix
The International System of Units, known by the international abbreviation SI in all languages and sometimes pleonastically as the SI system, is the modern form of the metric system and the world's most widely used system of measurement. ...
for a factor of . The centimetre was the base unit of length in the now deprecated
centimetre–gram–second (CGS) system of units.
Though for many physical quantities,
SI prefix
The International System of Units, known by the international abbreviation SI in all languages and sometimes pleonastically as the SI system, is the modern form of the metric system and the world's most widely used system of measurement. ...
es for factors of 10
3—like ''milli-'' and ''kilo-''—are often preferred by technicians, the centimetre remains a practical unit of length for many everyday measurements. A centimetre is approximately the width of the fingernail of an average adult person.
Equivalence to other units of length
:
One
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
Length is a measure of distance. In the International System of Quantities, length is a quantity with dimension distance. In most systems of measurement a base unit for length is chosen, from which all other units are derived. In the Inte ...
, the centimetre is used:
* sometimes, to report the level of rainfall as measured by a
rain gauge
A rain gauge (also known as udometer, pluvia metior, pluviometer, ombrometer, and hyetometer) is an instrument used by meteorologists and hydrologists to gather and measure the amount of liquid precipitation over a predefined area, over a period ...
* in the
CGS system, the centimetre is used to measure
capacitance
Capacitance is the capability of a material object or device to store electric charge. It is measured by the change in charge in response to a difference in electric potential, expressed as the ratio of those quantities. Commonly recognized a ...
, where 1 cm of capacitance =
farad
The farad (symbol: F) is the unit of electrical capacitance, the ability of a body to store an electrical charge, in the International System of Units (SI). It is named after the English physicist Michael Faraday (1791–1867). In SI base unit ...
s
* in maps, centimetres are used to make conversions from map scale to real world scale (kilometres)
* to represent second moment of areas (cm
4)
* 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 physics, the wavelength is the spatial period of a periodic wave—the distance over which the wave's shape repeats.
It is the distance between consecutive corresponding points of the same phase on the wave, such as two adjacent crests, tr ...
in centimetres). The SI unit of wavenumber is the inverse metre, m
−1.
Unicode symbols
For the purposes of compatibility with
Chinese,
Japanese and
Korea
Korea ( ko, 한국, or , ) is a peninsular region in East Asia. Since 1945, it has been divided at or near the 38th parallel, with North Korea (Democratic People's Republic of Korea) comprising its northern half and South Korea (Republi ...
n (
CJK) characters,
Unicode
Unicode, formally The Unicode Standard,The formal version reference is is an information technology standard for the consistent encoding, representation, and handling of text expressed in most of the world's writing systems. The standard, ...
has symbols for:
CJK Compatibility excerpt
from The Unicode Standard, Version 10.0.
* centimetre –
* square centimetre –
* cubic centimetre –
They are mostly used only with East Asian fixed-width CJK fonts, because they are equal in size to one Chinese character.
See also
* Conversion of units
* Orders of magnitude (length)
* Reciprocal length
References
{{Authority control
Metre
-02
Centimetre–gram–second system of units
SI units
100 (number)