Speed Converter
Convert speeds between kilometers per hour, meters per second, miles per hour and knots. Ideal for running, sailing or physics.
Speed conversion
Result
100 km/h =
27,777778 m/s
Meters per second
1 knot = 1.852 km/h · To go from m/s to km/h: multiply by 3.6.
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How to use: Speed
- 1Type the speed.
- 2Pick the source unit (km/h, m/s, mph, knots, ft/s or Mach) and the target unit.
- 3Read the result and the table with every unit.
What is it for?
- Turn mph speed limits into km/h (or back) when driving abroad.
- Convert knots to km/h for sailing or aviation.
- Switch m/s to km/h for physics problems or wind data.
Speed units and where they are used
When each one is used
Kilometers per hour dominate on roads in most countries; miles per hour in the US and UK; meters per second in physics and meteorology; the knot (1.852 km/h) in maritime and air navigation. The Mach number expresses speed relative to the speed of sound.
Converting by hand
From m/s to km/h multiply by 3.6, and from km/h to m/s divide by 3.6. From mph to km/h multiply by 1.609344. One knot is 0.514 m/s.
Mach is not fixed
The speed of sound depends on air temperature: about 343 m/s (1,235 km/h) at 20 °C, dropping to around 295 m/s at an airliner's cruising altitude. That is why Mach 1 does not correspond to a single km/h value.
Related tools
Frequently asked questions
How many km/h is a knot?+
1 knot equals exactly 1.852 km/h. It's the standard unit in maritime and air navigation.
How do I go from m/s to km/h?+
Multiply by 3.6. For example, 10 m/s is 36 km/h.