Speed Converter
Convert km/h, mph, m/s, knots and mach.
| Metres per secondm/s | 0.2778 | |
| Kilometres per hourkm/h | 1 | |
| Miles per hourmph | 0.6214 | |
| Feet per secondft/s | 0.9113 | |
| Knotkn | 0.54 | |
| Mach (sea level)M | 0.0008 |
All conversions go through the metre per second using exact internationally agreed factors; only the display is rounded.
About Speed Converter
Speed limits, weather reports, running apps and flight trackers all use different units, and the mental arithmetic for converting between them is rarely accurate enough to rely on.
This converter handles every common speed unit at once and adds running pace in minutes per kilometre and per mile.
How Speed Converter works in your browser
Speeds are converted through metres per second using exact factors: a knot is one nautical mile (1852 m) per hour, and a mile per hour is 0.44704 m/s. Mach has no fixed value because the speed of sound depends on temperature, so the converter uses the standard sea-level figure.
Running pace is the inverse of speed, so it is shown separately as minutes per kilometre and per mile rather than as another multiplier.
When to use it
- Converting a treadmill speed in km/h into a running pace per mile.
- Reading wind speeds or boat speeds quoted in knots.
- Checking speed limits when driving in a country that uses the other system.
Frequently asked questions
How do I convert km/h to mph?
Divide by 1.609344. So 100 km/h is about 62 mph.
What pace is 10 km/h?
Six minutes per kilometre, or about 9 minutes 39 seconds per mile. Pace is the inverse of speed, so the tool shows both.
What is a knot?
One nautical mile per hour, roughly 1.852 km/h, used in marine and aviation contexts.
Is mach a fixed speed?
No. It is the ratio to the local speed of sound, which varies with temperature. The converter uses the standard sea-level value of 1225 km/h.
How do I convert running pace?
Pace is the inverse of speed. The tool shows minutes per kilometre and per mile alongside the speed units.