Kilometers per Hour to Miles per Hour Converter

The conversion factor

One kilometer equals 0.621371 miles, so the tool multiplies your input by that factor: mph = km/h × 0.621371. This factor derives from the exact definition of a mile as 1,609.344 meters (1 ÷ 1.609344 = 0.621371...).

Worked example

Enter 100 km/h and the tool returns 62.14 mph (100 × 0.621371 = 62.1371, rounded to two decimals). That's roughly the difference between a car doing 100 on a European highway and the same car reading 62 on a US speedometer.

Reference speeds

This is why 100 km/h speed limits (common outside North America) read close to 62 mph, and why 130 km/h European highway limits translate to roughly 80 mph.