🚀 Speed converter
Convert between miles per hour, kilometers per hour, meters per second and knots. Enter a value and pick its unit to see it in every other unit.
Popular speed conversions
| Conversion | Rate |
|---|---|
| Miles Per Hour to kilometers per hour | 1 mph = 1.609344 km/h |
| Kilometers Per Hour to miles per hour | 1 km/h = 0.62137119 mph |
| Meters Per Second to miles per hour | 1 m/s = 2.2369363 mph |
| Knots to miles per hour | 1 kn = 1.1507794 mph |
| Knots to kilometers per hour | 1 kn = 1.852 km/h |
| Meters Per Second to kilometers per hour | 1 m/s = 3.6 km/h |
Quick answers
- 50 mph to km/h
- 100 mph to km/h
- 150 mph to km/h
- 200 mph to km/h
- 250 mph to km/h
- 300 mph to km/h
- 50 km/h to mph
- 100 km/h to mph
- 150 km/h to mph
- 200 km/h to mph
- 300 km/h to mph
- 400 km/h to mph
About speed units
One mile per hour is exactly 1.609344 km/h. For a rough answer in your head, multiply mph by 1.6 to get km/h, or multiply km/h by 0.62 to get mph.
Knots are nautical miles per hour and are used at sea and in aviation.
Speed units
| Unit | Symbol | In meters per second |
|---|---|---|
| Kilometer Per Hour | km/h | 0.2777777778 m/s |
| Mile Per Hour | mph | 0.44704 m/s |
| Meter Per Second | m/s | 1 m/s |
| Foot Per Second | ft/s | 0.3048 m/s |
| Knot | kn | 0.5144444444 m/s |
| Mach | Mach | 340.29 m/s |
All speed conversions
From kilometers per hour
From miles per hour
From meters per second
From feet per second
From knots
From Mach
Speed unit definitions
- Kilometer Per Hour (km/h)
- Kilometers per hour is the speed unit on road signs and speedometers in most of the world.
- Mile Per Hour (mph)
- Miles per hour is the road speed unit in the United States and the United Kingdom.
- Meter Per Second (m/s)
- Meters per second is the SI unit of speed. Wind speed and physics problems are usually given in m/s.
- Foot Per Second (ft/s)
- Feet per second is used for projectile velocities and fluid flow in US engineering.
- Knot (kn)
- A knot is one nautical mile per hour, about 1.852 km/h. Ships, aircraft and wind forecasts for sailors use knots.
- Mach (Mach)
- Mach 1 is the speed of sound. This converter uses 340.29 m/s, the speed of sound in air at sea level and 15 °C; the real value falls with altitude.