Convert Miles per Hour to Kilometres per Hour

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

Conversion Formula

km/h = mph × 1.609344

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 Hour

A kilometre per hour (km/h) = 1/3.6 m/s - the universal road speed unit across most of the world. Walking pace ~5-6 km/h; jogging 9-12 km/h; elite marathon runners average 20-21 km/h. High-speed rail (TGV, Shinkansen, ICE) 250-350 km/h; TGV record 574.8 km/h. Category 5 hurricane ≥252 km/h; Thrust SSC land speed record 1,228 km/h (Mach 1.02). 1 km/h = 0.2778 m/s = 0.6214 mph = 0.5400 kn.

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