Convert Miles per Hour to Kilometres per Second

Convert Miles per Hour (mph) to Kilometres per Second (km/s) instantly and accurately.

Conversion Formula

km/s = mph × 0.00044704

About Miles per Hour

A mile per hour (mph) = exactly 0.44704 m/s - the primary road speed unit in the US, UK, and a few other countries. US interstate limits 65-85 mph; UK motorway 70 mph. Walking ~3-4 mph; club cycling 20-25 mph. MLB elite fastball 100 mph (44.7 m/s). Saffir-Simpson Category 5 hurricane ≥157 mph. Boeing 737 MAX cruises at ~521 mph (Mach 0.79). 1 mph = 0.44704 m/s = 1.60934 km/h = 0.86898 kn.

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.

Quick Reference Table

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