Kilometer (km)
The kilometre (km) is 1000 metres. It is the standard unit for road distances and speed limits outside the US and UK.
Symbol: km
Quantity: length and distance
SI relation: 1 km = 1000 m (exact)
Derivation: 1 km = 10³ m
Exact: yes, by definition
Typical uses
- Road distances and speed (km/h)
- Running races (5 km, 10 km, marathon 42.195 km)
- Geography and mapping
Convert kilometers to other units
| Conversion | 1 km equals | Reverse |
|---|---|---|
| kilometer to meter | 1000 m | meter to kilometer |
| kilometer to centimeter | 100000 cm | centimeter to kilometer |
| kilometer to millimeter | 1000000 mm | millimeter to kilometer |
| kilometer to mile | 0.6213711922 mi | mile to kilometer |
| kilometer to foot | 3280.839895 ft | foot to kilometer |
| kilometer to inch | 39370.07874 in | inch to kilometer |
| kilometer to micrometer | 1000000000 µm | micrometer to kilometer |
| kilometer to nanometer | 1000000000000 nm | nanometer to kilometer |
| kilometer to yard | 1093.613298 yd | yard to kilometer |
| kilometer to nautical mile | 0.5399568035 nmi | nautical mile to kilometer |
| kilometer to angstrom | 10000000000000 Å | angstrom to kilometer |
| kilometer to mil | 39370078.74 mil | mil to kilometer |
Open the Length Converter to convert any value between all units.
Sources
- The International System of Units (SI), 9th edition (SI Brochure), Bureau International des Poids et Mesures , Table 7, SI prefixes.
Last reviewed: . Factors are stored exactly and computed with 50-digit decimal arithmetic. See how we verify conversion factors.
Cite this page
APA
Scientific Converters. (2026, October 15). Kilometer (km). Retrieved October 17, 2026, from https://scientificconverters.com/units/kilometer/
IEEE
Scientific Converters, "Kilometer (km)," scientificconverters.com. Accessed: Oct. 17, 2026. [Online]. Available: https://scientificconverters.com/units/kilometer/