Speed Converter
Convert speeds for driving, running, sailing, flying and weather reports. All four units here are defined exactly in terms of meters and seconds.
miles per hour
1 km/h = 0.6214 mph
Popular speed conversions
Units in this converter
| Unit | Symbol | Equals (in meters per second) |
|---|---|---|
| Meter per second | m/s | 1 m/s |
| Kilometer per hour | km/h | 0.277777777778 m/s |
| Mile per hour | mph | 0.44704 m/s |
| Knot | kn | 0.514444444444 m/s |
About the units
- Meter per second (m/s)
- Meters per second is the SI unit of speed. Physics problems use it, and many weather services report wind speed in m/s.
- Kilometer per hour (km/h)
- Kilometers per hour is the unit on speed-limit signs and speedometers in most of the world. 1 km/h equals 1/3.6 m/s, or about 0.278 m/s.
- Mile per hour (mph)
- Miles per hour is the road speed unit in the US and the UK. One mile per hour is exactly 1.609344 km/h.
- Knot (kn)
- A knot is one nautical mile (1,852 m) per hour, exactly 1.852 km/h. Ships, aircraft and marine weather forecasts use knots.
Frequently asked questions
How do I convert km/h to m/s quickly?
Divide by 3.6. For example, 90 km/h ÷ 3.6 = 25 m/s. To go from m/s to km/h, multiply by 3.6.
Why do ships and aircraft use knots?
A knot is one nautical mile per hour, and a nautical mile is tied to latitude: one minute of arc along a meridian is about one nautical mile. That makes knots convenient for navigation with charts.