Speed Converters
Speed converters let you translate between the units used on road signs (miles per hour or kilometers per hour), in sport and science (meters per second), and at sea or in the air (knots). They are handy when driving abroad, reading a car's specifications, interpreting a weather forecast or comparing athletic performance across countries.
All speed converters
Things to know about speed conversions
- Speed limits are in miles per hour in the US and UK and in kilometers per hour in most other countries. 100 km/h is about 62 mph.
- A knot is one nautical mile per hour (about 1.852 km/h, or 1.151 mph) and is used at sea and in aviation.
- Meters per second is the SI unit. Multiply by 3.6 to get kilometers per hour.
Speed conversion chart
Read across: one of the unit in the left column equals the value shown under each unit.
| 1 unit = | m/s | km/h | mph | ft/s | kn |
|---|---|---|---|---|---|
| m/s | 1 | 3.6 | 2.237 | 3.281 | 1.944 |
| km/h | 0.2778 | 1 | 0.6214 | 0.9113 | 0.54 |
| mph | 0.447 | 1.609 | 1 | 1.467 | 0.869 |
| ft/s | 0.3048 | 1.097 | 0.6818 | 1 | 0.5925 |
| kn | 0.5144 | 1.852 | 1.151 | 1.688 | 1 |
Speed units explained
- Meter per second (m/s)
- Meters per second is the SI unit of speed and is common in physics, engineering and weather reports for wind.
- Kilometer per hour (km/h)
- Kilometers per hour is the road speed unit used in most countries. 100 km/h is about 62 mph.
- Mile per hour (mph)
- Miles per hour is exactly 0.44704 meters per second. It is used for road speeds in the US and UK.
- Foot per second (ft/s)
- Feet per second is used in ballistics, engineering and some sports. One ft/s is about 0.68 mph.
- Knot (kn)
- A knot is one nautical mile per hour, about 1.852 km/h. It is the standard unit for ships and aircraft.