About the KM/H to MPH Converter
This km/h to mph converter turns a speed in kilometers per hour into miles per hour, along with meters per second, feet per second and knots. It is exact, using the international mile of 1,609.344 meters.
Use it when driving abroad and reading metric speed limits, comparing car top speeds or 0–100 km/h figures, reading wind speeds in forecasts, or converting running, cycling and train speeds from metric sources.
One km/h is about 0.621 mph, so common limits are easy to remember: 50 km/h ≈ 31 mph, 100 km/h ≈ 62 mph and 130 km/h ≈ 81 mph. The table below lists the usual posted limits.
With the default inputs, the miles per hour is 62.137 mph. Change any value above to recalculate instantly.
How to use the km/h to mph converter
- 1Enter the speed in km/h.
- 2Read the equivalent in mph.
- 3Use m/s for physics or wind, and knots for boats and aircraft.
- 4Check the table for typical speed limits.
Formula and method
Both units measure distance per hour, so only the distance unit changes: kilometers are converted to meters and divided by the exact length of a mile, 1,609.344 m. The result is the same as multiplying by 0.621371.
Meters per second divide km/h by 3.6 (1,000 m ÷ 3,600 s). Knots are nautical miles per hour, where one nautical mile is exactly 1,852 m. Feet per second use 1 ft = 0.3048 m.
- km/h
- Speed in kilometers per hour
- mph
- Speed in miles per hour
Worked examples
Motorway speed of 100 km/h
100,000 m ÷ 1,609.344 = 62.14 mph. In one second you travel 100 ÷ 3.6 = 27.8 m.
Urban limit of 50 km/h
50 km/h is 31.07 mph, or about 45.6 feet every second.
French autoroute limit of 130 km/h
130 × 0.621371 = 80.78 mph, about 11 mph faster than the 70 mph UK motorway limit.
Frequently asked questions
How do I convert km/h to mph?+
Multiply km/h by 0.621371 (or divide by 1.609344). For a quick estimate, multiply by 6 and divide by 10: 80 km/h ≈ 48 mph (exactly 49.7).
What is 100 km/h in mph?+
100 km/h is 62.14 mph. That is the standard reference speed behind "0–100 km/h" acceleration times, the metric version of 0–60 mph.
Is kph the same as km/h?+
Yes. kph, km/h and kmh all mean kilometers per hour. km/h is the official SI-style symbol; kph is common informal shorthand.
How do I convert km/h to meters per second?+
Divide by 3.6, because one kilometer per hour is 1,000 meters per 3,600 seconds. So 36 km/h is exactly 10 m/s.
What is a knot?+
A knot is one nautical mile (1,852 m) per hour, about 1.852 km/h or 1.151 mph. It is used for ships, aircraft and wind speed.
Sources