Speed Converter
Convert instantly between km/h, mph, m/s, ft/s and knots.
How to Use
- Enter a value and choose the unit you're converting from.
- Choose the unit you want to convert to.
- The result updates instantly as you type — there's no Convert button to press.
- Use the swap button to reverse the conversion direction.
Formula
value_in_target_unit = value × (from_unit_to_mps ÷ to_unit_to_mps). Every unit converts through meters per second as the common base.
Worked Example
Convert 100 km/h to mph.
- 100 km/h = 100,000 meters ÷ 3,600 seconds = 27.777... m/s.
- 27.777... m/s ÷ 0.44704 (m/s per mph) ≈ 62.1371 mph.
Result: 62.1371 mph
Conversion Table
| Unit | Symbol |
|---|---|
| Meters per Second | m/s |
| Kilometers per Hour | km/h |
| Miles per Hour | mph |
| Feet per Second | ft/s |
| Knots | kn |
About This Tool
What this tool does
Converts a speed value between the units most commonly used for vehicles, wind, and general motion: kilometers per hour, miles per hour, meters per second, feet per second, and knots.
When to use it
Use it to translate a speed limit, wind speed, vehicle spec, or vessel/aircraft speed between different regions' or industries' preferred units.
What the result means
The result is the equivalent speed in the target unit, rounded to a readable number of decimal places without losing meaningful precision.
Assumptions & limitations
All factors are exact, derived from exact length/time definitions (1 mph = 1609.344 ÷ 3600 m/s exactly; 1 knot = 1 international nautical mile [1852 m exactly] per hour). Mach is deliberately not included: the speed of sound depends on the medium's temperature and altitude, so there is no single fixed "1 Mach = X m/s" conversion factor to offer.