Speed Converter
Convert speeds for driving, aviation, sailing, weather and physics between m/s, km/h, mph and knots.
Result
Enter a value to convert.
How to use this calculator
- Enter a speed and select the from and to units.
- Use the swap button to reverse.
- Every unit is listed in the table.
Formula
Every unit is converted through meters per second:
- 1 km/h = 1,000 m ÷ 3,600 s ≈ 0.27778 m/s
- 1 mph = 1,609.344 m ÷ 3,600 s = 0.44704 m/s
- 1 knot = 1 nautical mile (1,852 m) per hour ≈ 0.51444 m/s
Worked example
100 km/h
100 km/h = 62.13711922 mph = 27.77777778 m/s.
20 knots in km/h
20 × 1.852 = 37.04 km/h.
Assumptions and limitations
- The knot uses the international nautical mile of exactly 1,852 m.
- For running and cycling pace (minutes per km or mile), use the Pace Calculator.
Frequently asked questions
How do I convert km/h to mph quickly?
Multiply by about 0.621, or divide by 1.609. For example, 100 km/h ≈ 62 mph.
Why do ships and aircraft use knots?
A nautical mile is based on one minute of latitude, which makes navigation with charts simpler.