Kilometre (km)
The kilometre (symbol km) is a unit of length in the International System of Units (SI) equal to 1,000 metres. Established during the French Revolution in 1795 as part of the decimal metric system, it is now the world's most widely used unit for expressing geographical distances between land locations, road lengths, and speed limits, with the notable exceptions of the United States and the United Kingdom where miles remain standard.
Metric
- Kilometre (km)1
- Metre (m)1,000
- Decimetre (dm)10,000
- Centimetre (cm)100,000
- Millimetre (mm)1,000,000
- Micrometre (µm)1×10⁹
- Nanometre (nm)1×10¹²
- Angstrom (Å)1×10¹³
Nautical
- Nautical mile0.54
- Fathom546.81
Astronomical
- Parsec (pc)3.24×10⁻¹⁴
- Light year1.06×10⁻¹³
- Astronomical unit (AE)6.68×10⁻⁹
- Light minute5.56×10⁻⁸
- Light second3.34×10⁻⁶