KM/H to MPH Converter
Enter a speed in kilometers per hour to see it in miles per hour right away. Edit either box and the other updates live. The math runs in your browser.
How to convert km/h to mph
- Type the speed in kilometers per hour into the left box.
- Read the miles per hour value in the right box as it updates live.
- Edit the mph box instead to convert back to km/h.
Examples
Highway speed
100 km/h
62.14 mph
Motorway limit
120 km/h
74.56 mph
Frequently asked questions
What is the formula to convert km/h to mph?
Multiply the km/h value by 0.621371. So mph = km/h times 0.621371. For example, 100 km/h becomes 100 times 0.621371, which is about 62.14 mph.
I am driving abroad. What do common speed limits convert to?
A 50 km/h town limit is about 31 mph, 80 km/h is about 50 mph, 100 km/h is about 62 mph, and a 130 km/h motorway limit is about 81 mph.
What are some common km/h to mph conversions?
30 km/h is about 18.6 mph, 60 km/h is about 37.3 mph, 90 km/h is about 55.9 mph, and 120 km/h is about 74.6 mph.
What is the difference between km/h and mph?
Both measure speed, but km/h counts kilometers covered per hour while mph counts miles. Since a mile is longer than a kilometer, a given speed is a smaller number in mph than in km/h.
Is this conversion exact?
The factor 0.621371 is a rounded form of the exact ratio (1 mile is exactly 1.609344 km). The calculation uses full precision and only rounds the result for display, so it is accurate for everyday use.
Is my data sent anywhere?
No. The conversion runs entirely in your browser, so the speeds you enter never leave your device.
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