Kilometer per Second (km/s)
Symbol: km/sWorldwide
A kilometer per second (km/s) is a metric unit of speed equal to exactly 1,000 meters per second or 3,600 kilometers per hour. It is convenient for describing speeds far above those encountered in everyday transport, including spacecraft, meteors and astronomical motion.
Quick Converter
What is a Kilometer per Second (km/s)?
A kilometer per second (km/s) is a metric unit of speed equal to exactly 1,000 meters per second or 3,600 kilometers per hour. It is convenient for describing speeds far above those encountered in everyday transport, including spacecraft, meteors and astronomical motion.
History
The kilometer per second derives from the meter and second in the International System of Units. Although m/s is the coherent SI unit of speed, km/s provides a more readable scale for very fast objects.
Current Use
Astronomers, aerospace engineers and geophysicists use km/s for orbital velocity, escape velocity, meteor entry and seismic-wave propagation.
Everyday Use
Astronomers, aerospace engineers and geophysicists use km/s for orbital velocity, escape velocity, meteor entry and seismic-wave propagation.
In Science & Industry
Astronomers, aerospace engineers and geophysicists use km/s for orbital velocity, escape velocity, meteor entry and seismic-wave propagation.
Conversion Table
| Unit | Value | |
|---|---|---|
| Meter per Second (m/s) | 1,000 | |
| Kilometer per Hour (km/h) | 3,600 | |
| Mach (M) | 2.915452 | M → km/s |