KM/H to MPH formula
1 kilometre per hour = 0.6213711922 miles per hour, and 1 mile per hour = 1.609344 kilometres per hour. 1,000 m in 3,600 s: exactly 1/3.6 m/s. Speed limits in most countries.
KM/H to MPH chart
| Kilometres per hour (km/h) | Miles per hour (mph) |
|---|---|
| 10 | 6.2137 |
| 20 | 12.4274 |
| 25 | 15.5343 |
| 30 | 18.6411 |
| 40 | 24.8548 |
| 50 | 31.0686 |
| 60 | 37.2823 |
| 70 | 43.496 |
| 80 | 49.7097 |
| 90 | 55.9234 |
| 100 | 62.1371 |
| 110 | 68.3508 |
| 120 | 74.5645 |
| 130 | 80.7783 |
| 140 | 86.992 |
| 150 | 93.2057 |
| 160 | 99.4194 |
| 180 | 111.8468 |
| 200 | 124.2742 |
Values are rounded to 4 decimal places. The converter above shows more precision.
Worked examples
A 100 km/h limit on a rural road
100 km/h ÷ 1.609344 = 62.1371 mph
100 kilometres per hour = 62.1371 miles per hour. About 62 mph, close to the 60 mph limit on UK single-carriageway roads.
The French motorway limit of 130 km/h
130 km/h ÷ 1.609344 = 80.7783 mph
130 kilometres per hour = 80.7783 miles per hour. Almost 81 mph, so noticeably faster than the 70 mph allowed on UK motorways.
Converting kilometres per hour to miles per hour in real life
Visitors from the US or the UK driving in Europe, Asia or Australia meet speed limits in km/h and speedometers that may show both units. Cyclists and runners also compare speeds across apps: a 25 km/h e-bike limit in the EU is about 15.5 mph, while US e-bike classes are set at 20 and 28 mph.
For a quick mental check, take the km/h figure, halve it, and add a fifth of the half: 100 → 50 + 10 = 60 mph (the exact answer is 62.1). The precise factor comes from the international mile of 1,609.344 m. For distances, use km to miles.