How to use this calculator
- Enter a speed.
- Choose the from and to units.
Formula
Speed units combine a length and a time unit.
1 mph = 1.609344 km/h = 0.44704 m/s
1 knot = 1 nautical mile per hour = 1.852 km/h
1 m/s = 3.6 km/h
Mach 1 ≈ 340.29 m/s (sea level, 15 °C)
Examples
- 60 mph × 1.609344 = 96.56 km/h.
- 100 km/h ÷ 1.609344 = 62.14 mph.
Frequently asked questions
Why is Mach approximate?
The speed of sound depends on air temperature. This converter uses the standard sea-level value of 340.29 m/s.
Where are knots used?
In aviation and at sea, because one nautical mile corresponds to one minute of latitude.
How do I convert running pace to speed?
Use the pace calculator, which converts min/km and min/mile into km/h and mph.