Metres per second to kilometres per hour – and kilometres per hour to metres per second

Formula

Multiply the value in metres per second by 3.6 to get kilometres per hour.
km/h = m/s × 3.6

Multiply the value in kilometres per hour by 0.27777778 to get metres per second.
m/s = km/h × 0.27777778

How to convert metres per second to kilometres per hour

Type a value in the field above and the result is calculated instantly. Use the arrow button to swap direction, or pick other units from the lists.

Doing it in your head

A rough conversion for when the calculator is not to hand. The error comes last, and it holds in both directions at that order of magnitude.

• Kilometres per hour to metres per second: ÷ 4 + 10%. That gives 0.275 instead of 0.277778, an error of 1%.

About the units

Metres per second. The metre per second is the SI coherent unit of speed, formed directly from the metre and the second, and the unit every other speed measure is converted through. It is a legal unit across the EU and the obvious one in physics and engineering. Ten metres per second is 36 kilometres per hour, and one metre per second is 2.24 miles per hour. The factor against kilometres per hour is 3.6 and is often dropped. At sea and in the air, speed is counted in knots.

Kilometres per hour. The kilometre per hour is built from two legal units and is itself legal throughout the EU. One kilometre per hour is one 3.6th of a metre per second. It is the unit on speedometers and speed limits across the union, and Swedish traffic rules set the limits in kilometres per hour, 50 in built-up areas and 70 outside them. A hundred kilometres per hour is just under 28 metres per second and 62 miles per hour. Write km/h, not “kmh” or “kph”.