How this calculator works
Metres per second and kilometres per hour both measure speed, but one uses the base SI unit and the other uses a unit that suits road traffic. One kilometre is 1,000 metres and one hour is 3,600 seconds, so 1 km/h is 1,000/3,600 m/s, or 0.277778 m/s. Multiplying m/s by 3.6 gives km/h. The same conversion chain reaches miles per hour, feet per second and knots through the exact definitions of those units.
Formula
m/s = value x F(unit), where F is: m/s 1, km/h 1/3.6, mph 0.44704, ft/s 0.3048 and knots 1,852/3,600. km/h = m/s x 3.6. mph = m/s / 0.44704. ft/s = m/s / 0.3048. km/s = m/s / 1,000.
Worked example
10 m/s is 36 km/h, 22.369 mph, 32.808 ft/s and 19.438 knots. 100 km/h is 27.778 m/s. 60 mph is 26.822 m/s or 96.561 km/h.
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Frequently asked questions
Why multiply by 3.6 to get km/h?
One hour has 3,600 seconds and one kilometre has 1,000 metres, so 1 m/s is 3,600/1,000 km/h, which is 3.6 km/h.
Is 10 m/s fast?
Ten metres per second is 36 km/h or 22.4 mph, about the speed of a fast bicycle or a slow city street. Usain Bolt's 100 m world record averaged about 10.44 m/s.
Why does the page show knots as well?
Knots are used in marine and aviation navigation. One knot is one nautical mile per hour, exactly 1,852 m/h, so it can be converted from any other speed without a time-zone or altitude correction.