Convert Kilometres per Hour to Kilometres per Second

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

Kilometres per Hour (km/h)
Kilometres per Second (km/s)

Conversion Formula

km/s = km/h × 0.0002777777778

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.

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

Kilometres per Hour (km/h)Kilometres per Second (km/s)
1 km/h0.000277778 km/s
2 km/h0.000555556 km/s
5 km/h0.00138889 km/s
10 km/h0.00277778 km/s
25 km/h0.00694444 km/s
50 km/h0.0138889 km/s
100 km/h0.0277778 km/s

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