Centimetre

File:EM Spectrum Properties edit.svg

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 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 Template:Sfrac.<ref>Template:Cite web</ref> Equivalently, there are 100 centimetres in 1 metre. 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 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.<ref>Template:Cite web</ref><ref>Template:Cite book</ref> A centimetre is approximately the width of the fingernail of an average adult person.

Equivalence to other units of length

Template:Calculator centimetre	= Template:Calculator millimetres
	= Template:Calculator metres
	= Template:Calculator inches (There are exactly 2.54 centimetres in one inch.)

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, the centimetre is used:

• sometimes, to report the level of rainfall as measured by a rain gauge<ref>Template:Cite web</ref>
• in the CGS system, the centimetre is used to measure capacitance, where 1 cm of capacitance = Template:Val farads<ref>Template:Cite web</ref>
• 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.

Unicode symbols

For the purposes of compatibility with Chinese, Japanese and Korean (CJK) characters, Unicode has symbols for:<ref>CJK Compatibility excerpt from The Unicode Standard, Version 10.0.</ref>

• centimetre – Template:Unichar
• square centimetre – Template:Unichar
• cubic centimetre – Template:Unichar

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

External links

• CM to Inch Converter