Convert between km/h, mph, m/s, ft/s, knots, and Mach with live results and formulas.
This tool converts between six common speed units by first converting the input value to meters per second (the SI unit), then converting from m/s to the target unit. Mach number is based on the speed of sound at sea level in dry air at 20°C, approximately 340.29 m/s. The conversion factor is displayed so you can verify every result.
| From | To | Factor |
|---|---|---|
| 1 km/h | mph | 0.621371 |
| 1 mph | km/h | 1.60934 |
| 1 m/s | km/h | 3.6 |
| 1 Knot | km/h | 1.852 |
| 1 Mach | km/h | 1225.04 |
| 1 ft/s | m/s | 0.3048 |
Different speed units are used in different contexts. Km/h and mph are standard for road vehicles. Knots are used in maritime and aviation because they directly relate to nautical miles. Mach is used in aerospace to express speed relative to the speed of sound. Scientists and engineers typically use m/s. This tool bridges all these contexts so you never have to look up a conversion factor again.