Kilometres per hour to miles per hour – and miles per hour to kilometres per hour
1 km/h = 0.62137119 mph
All units in this category
- 0.27777778m/s
- 1km/h
- 0.62137119mph
- 0.5399568kn
- 0.91134442ft/s
Formula
Multiply the value in kilometres per hour by 0.62137119 to get miles per hour.mph = km/h × 0.62137119
Multiply the value in miles per hour by 1.609344 to get kilometres per hour.km/h = mph × 1.609344
How to convert kilometres per hour to miles per hour
Type a value in the field above and the result is calculated instantly. Use the arrow button to swap direction, or pick other units from the lists.
Doing it in your head
A rough conversion for when the calculator is not to hand. The error comes last, and it holds in both directions at that order of magnitude.
- Kilometres per hour to miles per hour: × 5 ÷ 8. That gives 0.625 instead of 0.621371, an error of 0.58%.
- Miles per hour to kilometres per hour: × 2 − 20%. That gives 1.6 instead of 1.60934, an error of 0.58%.
Kilometres per hour to miles per hour – common values
| Kilometres per hour (km/h) | Miles per hour (mph) |
|---|---|
| 1 | 0.621371 |
| 5 | 3.10686 |
| 10 | 6.21371 |
| 20 | 12.4274 |
| 30 | 18.6411 |
| 50 | 31.0686 |
| 70 | 43.496 |
| 90 | 55.9234 |
| 100 | 62.1371 |
| 120 | 74.5645 |
Miles per hour to kilometres per hour – common values
| Miles per hour (mph) | Kilometres per hour (km/h) |
|---|---|
| 1 | 1.60934 |
| 5 | 8.04672 |
| 10 | 16.0934 |
| 20 | 32.1869 |
| 30 | 48.2803 |
| 50 | 80.4672 |
| 70 | 112.654 |
| 90 | 144.841 |
| 100 | 160.934 |
| 120 | 193.121 |
About the units
Kilometres per hour. The kilometre per hour is built from two legal units and is itself legal throughout the EU. One kilometre per hour is one 3.6th of a metre per second. It is the unit on speedometers and speed limits across the union, and Swedish traffic rules set the limits in kilometres per hour, 50 in built-up areas and 70 outside them. A hundred kilometres per hour is just under 28 metres per second and 62 miles per hour. Write km/h, not “kmh” or “kph”.
Miles per hour. A mile per hour is exactly 0.44704 metres per second, that is 1.609344 kilometres per hour. It is the unit on speedometers and road signs in the US and the UK, and EU law makes an explicit exception for British and Irish speed limits. American weather reports give wind in mph as well. Seventy miles per hour is 112.7 kilometres per hour. Two factors are easy to mix up: a mile per hour is 1.609 kilometres per hour, while a knot is 1.151 miles per hour.