# Centimetre

A **centimetre** (international spelling) or **centimeter** (American spelling) (SI symbol **cm**) is a unit of length in the metric system, equal to one hundredth of a metre, *centi* being the SI prefix for a factor of 1/100.[1] The centimetre was the base unit of length in the now deprecated centimetre–gram–second (CGS) system of units.

centimetre | |
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General information | |

Unit system | metric |

Unit of | length |

Symbol | cm |

Conversions | |

1 cm in ... | ... is equal to ... |

SI units | 10 mm |

imperial & US system | ~0.3937 in |

Look up in Wiktionary, the free dictionary.centimetre |

Though for many physical quantities, SI prefixes 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.