# Convert Millimetre [mm] to...

Millimetre | |
---|---|

Unit system | metric |

Unit of | length |

Symbol | mm |

Unit conversions | |

1 mm in ... |
... is equal to ... |

SI units | 1000 µm 1×10 ^{-3} m |

Imperial/US unit(s) | 0.039370 in |

**I want to convert:**
**using**

Metric | Conversion |
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Kilometre [km] | |

Hectometre [hm] | |

Decametre [dam] | |

Metre [m] | |

Decimetre [dm] | |

Centimetre [cm] | |

Millimetre [mm] | |

Micrometre [µm] | |

Nanometre [nm] | |

Angstrom [Å] |

British/Imperial | Conversion |
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League | |

Mile [mi] | |

Furlong | |

Chain | |

Rod [rd] | |

Yard [yd] | |

Foot [ft] | |

Link | |

Hand | |

Inch [in] | |

Line | |

Mil [mil] | |

Thou [thou] |

Nautical | Conversion |
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Sea mile | |

Fathom |

Astronomical | Conversion |
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Parsec [pc] | |

Light Year | |

Astronomical Unit [AE] | |

Light Minute | |

Light Second |

The **millimetre** (International spelling as used by the International Bureau of Weights and Measures) or **millimeter** (American spelling) (SI unit symbol mm) is a unit of length in the metric system, equal to one thousandth of a metre, which is the SI base unit of length.

It is equal to 1000 micrometres or 1000000 nanometres. A **millimetre** is equal to exactly 5/127 (approximately 0.039370) of an inch.

Since 1983, the metre has been defined as "the length of the path travelled by light in vacuum during a time interval of 1/299792458 of a second". A millimetre, 1/1000 of a metre, is therefore the distance travelled by light in 1/299792458000 of a second.

This article uses material from the Wikipedia article "Millimetre", which is released under the Creative Commons Attribution-Share-Alike License 3.0.