Convert Kilometres per Second to Miles per Second
Convert Kilometres per Second (km/s) to Miles per Second (mi/s) instantly and accurately.
Conversion Formula
mi/s = km/s × 0.6213711922
About Kilometres per Second
A kilometre per second (km/s) = 1,000 m/s - the scale of orbital mechanics and hypervelocity. ISS orbital speed ≈ 7.66 km/s; Earth escape velocity 11.186 km/s. Voyager 1 travels ~17 km/s relative to the Sun. Meteoroids enter Earth's atmosphere at 11-72 km/s; solar wind 400-800 km/s. High-explosive detonation fronts propagate at 6.9-8.8 km/s. 1 km/s = 3,600 km/h = 2,236.9 mph.
About Miles per Second
A mile per second (mi/s) = exactly 1,609.344 m/s - above the fastest air-breathing aircraft. NASA X-43A scramjet: 2.9 km/s ≈ 1.8 mi/s (Mach 9.6). Earth's orbital speed around the Sun: ~18.5 mi/s (29.8 km/s). Light travels ~186,282 mi/s in vacuum - the classic imperial figure still used in popular astronomy. Tunguska impactor entered Earth's atmosphere at ~9-11 mi/s. 1 mi/s = 3,600 mph = 3,128.3 kn.
Quick Reference Table
| Kilometres per Second (km/s) | Miles per Second (mi/s) |
|---|---|
| 1 km/s | 0.621371 mi/s |
| 2 km/s | 1.24274 mi/s |
| 5 km/s | 3.10686 mi/s |
| 10 km/s | 6.21371 mi/s |
| 25 km/s | 15.5343 mi/s |
| 50 km/s | 31.0686 mi/s |
| 100 km/s | 62.1371 mi/s |