Velocity & Speed Converter
Convert between 9 units of speed and velocity — km/h, mph, m/s, ft/s, knots, Mach, cm/s, km/s, and the speed of light.
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About the Velocity & Speed Converter
Speed measures the distance an object travels per unit of time. Different sectors use different units: road transport uses km/h or mph, aviation uses knots (nautical miles per hour), and physics prefers m/s. Mach number expresses speed relative to the local speed of sound, which varies with altitude and air temperature. The speed of light (c) is the universal speed limit at 299,792,458 m/s.
Quick facts
- ›The speed of light in a vacuum is exactly 299,792,458 m/s — a defined constant since 1983
- ›Mach 1 at sea level is approximately 340 m/s (1,235 km/h) at 15 °C
- ›The Parker Solar Probe reached ~163 km/s — the fastest human-made object ever
- ›Commercial airliners cruise at around 900 km/h (560 mph, Mach 0.85)
Common uses: Aviation, motorsport, meteorology, naval navigation, physics, athletics