Speed Converter

A speed converter changes a speed between units of distance per time: kilometres per hour, miles per hour, metres per second, knots or feet per second. Drivers meet it when renting a car abroad, runners when a treadmill shows mph, sailors and pilots with knots, and students with physics problems in m/s.

Enter a speed and choose the units to get the exact result, with the same speed shown in every other unit underneath. The factors are exact definitions, not rounded values.

1 m/s is exactly 3.6 km/h. A mile per hour is 1.609344 km/h, or 0.44704 m/s. A knot is one nautical mile per hour, exactly 1.852 km/h, and is the unit for wind speed at sea and aircraft airspeed.

Physics questions usually want metres per second, so multiplying or dividing by 3.6 is the conversion you'll use most.