Your result will appear here
Fill in the fields and press Calculate.
Miles per hour and kilometres per hour are the two common units of speed, split along the imperial/metric line. Speed limits, car speedometers and race paces cross between them, so this converter turns mph into km/h and back with a fixed factor.
How is it calculated?
The conversion factor
1 mph = 1.609344 km/h (and 1 km/h = 0.621371 mph).
| To convert | Do this |
|---|---|
| mph → km/h | multiply by 1.609344 |
| km/h → mph | divide by 1.609344 |
Common values
| mph | km/h |
|---|---|
| 30 mph | 48.28 km/h |
| 60 mph | 96.56 km/h |
| 70 mph | 112.65 km/h |
| 100 mph | 160.93 km/h |
Worked example
A 70 mph motorway limit is 70 × 1.609344 = 112.7 km/h. Going the other way, a 50 km/h urban limit is 50 ÷ 1.609344 = 31.1 mph. The two scales share the same factor as the distance conversion, since speed is just distance over time.
FAQ
How do I convert mph to km/h?+
Multiply the mph value by 1.609344. For example, 60 mph × 1.609344 = 96.56 km/h. A quick estimate is to multiply by 1.6.
How do I convert km/h to mph?+
Divide the km/h value by 1.609344, or multiply by 0.621371. So 100 km/h ÷ 1.609344 = 62.14 mph.
What is 60 mph in km/h?+
60 mph is 96.56 km/h. It’s a common highway speed, just under 100 km/h.
Is the conversion factor the same as miles to kilometres?+
Yes. Speed is distance divided by time, and the time unit (hours) is the same on both sides, so the mph-to-km/h factor is identical to the mile-to-kilometre factor: 1.609344.
What is 100 km/h in mph?+
100 km/h is about 62.14 mph — a touch over 62 mph, a typical open-road speed in metric countries.