Millimetre (mm)
The millimetre, denoted by the symbol mm, is an SI unit of length defined as one-thousandth of a metre (10⁻³ metres). First introduced during the French Revolution as part of the metric system's establishment in 1795, the millimetre is today derived directly from the fundamental SI metre defined by the speed of light. It serves as a standard unit across worldwide manufacturing, engineering, architecture, and meteorology.
Metric
- Kilometre (km)1×10⁻⁶
- Metre (m)1×10⁻³
- Decimetre (dm)0.01
- Centimetre (cm)0.1
- Millimetre (mm)1
- Micrometre (µm)1,000
- Nanometre (nm)1,000,000
- Angstrom (Å)10,000,000
Nautical
- Nautical mile5.4×10⁻⁷
- Fathom5.47×10⁻⁴
Astronomical
- Parsec (pc)3.24×10⁻²⁰
- Light year1.06×10⁻¹⁹
- Astronomical unit (au)6.68×10⁻¹⁵
- Light minute5.56×10⁻¹⁴
- Light second3.34×10⁻¹²