A carpenter's ruler with centimetre divisions
General information
Unit systemSI
Unit oflength
1 cm in ...... is equal to ...
   millimetres   10 mm
   imperial & US system   ~0.3937 in
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 spelling), 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.[1] 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.[2][3] A centimetre is approximately the width of the fingernail of an average adult person.

Equivalence to other units of length

1 centimetre = 10 millimetres
= 0.01 metres
= 0.393700787401574803149606299212598425196850 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:

Unicode symbols

For the purposes of compatibility with Chinese, Japanese and Korean (CJK) characters, Unicode has symbols for:[6]

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


  1. ^ "Decimal multiples and submultiples of SI units". Bureau International des Poids et Mesures. 2014. Retrieved 5 July 2015.
  2. ^ "Using the BMI-for-Age Growth Charts". cdc.gov. Centers for Disease Control. Archived from the original on 30 January 2014. Retrieved 5 July 2014.
  3. ^ Price, Beth; et al. (2009). MathsWorld Year 8 VELS Edition. Australia: MacMillan. p. 626. ISBN 978-0-7329-9251-4.
  4. ^ "Rain Measurement". www.weathershack.com.
  5. ^ Weisstein, Eric W. "Capacitance -- from Eric Weisstein's World of Physics". scienceworld.wolfram.com.
  6. ^ CJK Compatibility excerpt from The Unicode Standard, Version 10.0.