Convert Kilometer/Second (km/s) to Mile/Second (mi/s) instantly.
About these units
Kilometer/Second (km/s)
A kilometer per second represents a very high speed—1,000 meters every second—and is particularly important in astronomy, planetary science, and astrophysics. Orbital velocities around planets, escape velocities, solar winds, and the motion of stars relative to each other are commonly measured in km/s. This scale captures speeds far beyond terrestrial transportation. For example, Earth orbits the Sun at roughly 30 km/s, and meteoroids entering Earth's atmosphere may arrive at speeds between 11 and 72 km/s. km/s is a natural step up from m/s when describing the motion of celestial bodies.
Mile/Second (mi/s)
A mile per second is an extraordinarily fast speed—3,600 mph—far beyond any ground vehicle. This unit appears primarily in discussions of orbital mechanics, rocket propulsion, and reentry dynamics. Projectiles in theoretical physics or high-energy impact modeling may also be described in miles per second. The unit's infrequent use reflects its specialized nature, but its dramatic magnitude makes it compelling for illustrating the extremes of velocity attainable in space travel and astrophysics.