Speed Converter

Speed Converter

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Speed & Velocity Converter

Use the converter above to instantly convert between any two units of speed. This converter supports kilometers per hour, meters per second, miles per hour, knots, Mach, and feet per second — covering every speed conversion you are likely to need.

Whether you are converting speed limits while traveling, calculating wind speed, working with aviation data, or doing physics problems, this free converter gives you an instant accurate result.

How to convert speed units

Speed conversions are straightforward multiplications. The key relationship is that 1 mile = 1.60934 kilometers, so 1 mph = 1.60934 km/h. To convert km/h to mph, divide by 1.60934 (or multiply by 0.6214).

Meters per second is the SI standard unit for speed. To convert m/s to km/h, multiply by 3.6. To convert km/h to m/s, divide by 3.6. For example, 100 km/h ÷ 3.6 = 27.78 m/s.

Knots are used in aviation and maritime navigation. One knot equals one nautical mile per hour = 1.852 km/h = 1.15078 mph. Mach number is the ratio of speed to the speed of sound — Mach 1 ≈ 1,235 km/h at sea level, but this varies with temperature and altitude.

km/h to mph conversion table

km/h mph m/s
10 km/h6.214 mph2.778 m/s
30 km/h18.641 mph8.333 m/s
50 km/h31.069 mph13.889 m/s
60 km/h37.282 mph16.667 m/s
80 km/h49.710 mph22.222 m/s
100 km/h62.137 mph27.778 m/s
120 km/h74.565 mph33.333 m/s
150 km/h93.206 mph41.667 m/s
200 km/h124.274 mph55.556 m/s
300 km/h186.411 mph83.333 m/s

Frequently asked questions

How do I convert km/h to mph?
Divide by 1.60934 or multiply by 0.6214. So 100 km/h ÷ 1.60934 = 62.14 mph. A quick mental estimate: multiply km/h by 0.6 for a close approximation.
What is Mach 1 in km/h and mph?
Mach 1 ≈ 1,235 km/h (767 mph) at sea level at 15°C. The speed of sound changes with altitude and temperature — at cruising altitude it is approximately 1,062 km/h (660 mph).
How many km/h is 1 knot?
1 knot = 1.852 km/h = 1.15078 mph. Knots are nautical miles per hour, where 1 nautical mile = 1,852 meters. They are the standard unit in aviation and maritime navigation worldwide.
How do I convert m/s to km/h?
Multiply m/s by 3.6 to get km/h. For example, 10 m/s × 3.6 = 36 km/h. Going the other way, divide km/h by 3.6 to get m/s.
What is the speed of light in km/h?
The speed of light is approximately 1,079,252,849 km/h (about 1.079 billion km/h) or 299,792,458 meters per second. It is denoted as c and is a fundamental constant of the universe.