Speed Converter
Enter a speed and its unit to see the equivalent in meters per second, kilometers per hour, miles per hour, and knots.
How speed conversion works
Speed is distance divided by time, so converting between speed units means converting the distance and time parts together. For example, km/h to m/s divides by 3.6, because 1 km = 1000 m and 1 hour = 3600 s, and 1000/3600 = 1/3.6.
A knot is a nautical mile per hour, used in aviation and maritime navigation. 1 knot equals exactly 1.852 km/h, which is where the factor of 0.514444 m/s per knot comes from.
Frequently asked questions
How do I convert km/h to mph?
Divide by 1.609344 (since 1 mile = 1.609344 km), or multiply by approximately 0.621371.
Why is a knot different from mph?
A knot is based on the nautical mile (1,852 meters), which is a different unit from the statute mile (1,609.344 meters) used for mph — so 1 knot (1.852 km/h) is slightly faster than 1 mph (1.609 km/h).
How fast is 100 km/h in m/s?
100 km/h divided by 3.6 is approximately 27.78 m/s.