Speed Converter

Convert speed and velocity units

Convert between miles per hour, kilometers per hour, meters per second, knots and feet per second instantly. It's the quick answer for reading a foreign speed limit, comparing wind or vehicle speeds, or converting a physics result — with the exact rate shown below each conversion.

Common speed conversions

These are based on the exact definitions (1 mile = 1609.344 m, 1 nautical mile = 1852 m), so the conversions are precise.

How to convert speed by hand

Speed conversions are single multiplications by a fixed factor. Two worked examples:

• 60 mph to km/h: 60 × 1.609344 = 96.6 km/h.
• 100 km/h to mph: 100 ÷ 1.609344 = 62.1 mph.

Two shortcuts worth knowing: metres per second times 3.6 gives km/h, and a knot is 1.852 km/h (one nautical mile per hour). A rough driving rule of thumb is that 100 km/h is a little over 60 mph.

Speed conversions in everyday life

The obvious one is driving abroad, where speed-limit signs flip between mph and km/h at the border. Beyond that, runners and cyclists convert pace and speed, sailors and pilots work in knots, and weather reports quote wind speed in whichever unit is local. Getting it wrong on a motorway is an expensive mistake, so a quick check pays off.

Running rather than driving? The running pace calculator turns a distance and time into pace per km and mile. You can also switch to the length converter. For the classic case, read mph to km/h.

Frequently asked questions