Speed & Velocity Converter
Interactive StudioConvert between meters/second, km/h, mph, knots, feet/second, and Mach sound speed instantly. Instant feedback with zero server storage.
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About Speed & Velocity Converter
Speed represents the rate of displacement over time.
All conversions use standardized physical constants: 1 knot = 1 nautical mile per hour (1.852 km/h), 1 mph = 1.609344 km/h, and Mach 1 at standard sea-level atmospheric conditions is defined as 340.29 m/s (approx 1,225 km/h).
How to use Speed & Velocity Converter
- Type the value you want to convert.
- Choose the unit you are converting from and the unit you want, such as km/h, mph, m/s, knots or Mach.
- Read the converted value instantly. Swap the units to convert the other way.
- Copy the result, or check other units listed in the results grid.
Worked examples
Input: 100 km/h to mph
Result: About 62.14 mph.
Input: 100 km/h to knots
Result: About 54.0 knots.
Background
Conversions use exact definitions: 1 mph = 1.609344 km/h, 1 knot = 1.852 km/h (one nautical mile per hour) and 1 m/s = 3.6 km/h.
Mach is the ratio to the speed of sound, which varies with temperature and altitude. The tool uses the sea-level standard of 340.29 m/s, so Mach values at altitude will differ.
Common mistakes
- Treating Mach as a fixed speed. The speed of sound drops at altitude.
- Confusing knots with mph. A knot is about 15% faster.
- Dividing instead of multiplying when converting m/s to km/h. Multiply by 3.6.
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