Speed Converter
100 km/h is 62.14 mph, and 60 mph is 96.56 km/h.
How to use
- Enter a speed and choose the unit you have in From.
- Choose the unit you want in To. The main result updates as you type.
- The remaining units are listed below the result, and the table underneath shows common speeds in every unit.
How it works
Each unit is a fixed multiple of one metre per second, so a conversion is value × from factor ÷ to factor.
The factors are exact by definition: 1 mph = 0.44704 m/s, 1 knot = 1852 ÷ 3600 m/s (one nautical mile of 1852 m per hour), 1 ft/s = 0.3048 m/s and 1 km/h = 1 ÷ 3.6 m/s.
Mach is the one unit that is not a fixed constant. This tool uses the speed of sound in standard sea-level air at 15 °C, 340.29 m/s, so 1 Mach = 1225 km/h. The real speed of sound changes with air temperature and altitude, so the Mach number of a given airspeed in flight will differ.
FAQ
How many km/h is 1 mph?
Exactly 1.609344 km/h, because the international mile is defined as 1609.344 m and a km/h is 1000 m per hour.
What is a knot?
One nautical mile per hour, where a nautical mile is exactly 1852 m. It equals 1.852 km/h and about 1.15078 mph. Ships and aircraft commonly report speed in knots.
Which speed of sound does Mach use here?
340.29 m/s, the speed of sound in standard sea-level air at 15 °C. In the lower atmosphere the air gets colder with height, so sound travels slower there and the same speed is a higher Mach number.
Why are negative speeds rejected?
This converter treats speed as a magnitude. Enter the size of the speed without a sign.