Speed Converter

Speed Converter changes a speed between kilometres per hour, miles per hour, metres per second, feet per second, metres per minute and knots, and lists it in all of them at once. It is handy when a speed limit, a car’s top speed, a wind forecast or a treadmill reads in a unit you do not think in, and for physics problems that need metres per second. Each unit is defined exactly: a mile per hour is exactly 0.44704 metres per second because a mile is exactly 1,609.344 metres; a kilometre per hour is exactly 1/3.6 metres per second; a knot is one nautical mile (1,852 metres) per hour. The arithmetic is decimal, so 100 km/h comes out as 62.13711922 mph and back again without drifting.

1. Type the speed.
2. Choose its unit and the one you want, or press a common conversion.
3. Read the answer and the speed in every other unit.

• For speed from a distance and a time, or a running pace per kilometre, use the speed, distance and time calculator or the running pace calculator.
• Mach numbers depend on the temperature of the air, so they are not a fixed unit and are not included.
• Speedometers usually read a few per cent high on purpose, so a GPS speed may be lower than the dial shows.
• Everything runs in your browser; nothing you enter is sent.

About 62.14 mph. A quick estimate: multiply km/h by 5 and divide by 8.

Divide by 3.6. 72 km/h is 20 m/s; 36 km/h is 10 m/s.

One nautical mile per hour, exactly 1.852 km/h. Ships, aircraft and wind forecasts for sailors use it.

A mile per hour is faster than a kilometre per hour: 1 mph is 1.609 km/h. So 60 mph is about 97 km/h.

An easy walk is about 5 km/h (1.4 m/s). Running a kilometre in 5 minutes is 12 km/h, about 7.5 mph; a 4-minute kilometre is 15 km/h.