How many miles per hour are in a kilometer per hour?

1 km/h = 0.621371 mph. To convert any amount, multiply by 0.621371.

How do you convert kilometers per hour to miles per hour?

Multiply the number of kilometers per hour by 0.621371 to get miles per hour. The formula is shown in the "How it's calculated" section above.

Where does the conversion factor come from?

It's a published international standard. Most are defined exactly by international agreement (e.g. 1 inch = 25.4 mm exactly, 1 lb = 0.45359237 kg exactly). Source citations are listed under the formula above.

Unit converter — Velocity

Kilometers per hour to miles per hour converter

Convert kilometers per hour (km/h) to miles per hour (mph). Source-cited conversion factor, exact to the displayed precision.

Results are mathematically exact for the displayed precision. How we calculate.

How it's calculated

Convert kilometers per hour to miles per hour— the formula

Kilometers per hour convert to miles per hour by multiplying by the published conversion factor. The factor below is exact to the precision shown, sourced from the citation under the formula.

mph = km/h × 0.621371

km/h = mph × 1.6093

m/s: SI derived (m × s⁻¹). 1 km/h = 1000/3600 m/s; 1 mph = 0.44704 m/s exactly; 1 knot = 1852/3600 m/s exactly (international nautical mile).

Questions

Frequently asked questions

How many miles per hour are in a kilometer per hour?
1 km/h = 0.621371 mph. To convert any amount, multiply by 0.621371.
How do you convert kilometers per hour to miles per hour?
Multiply the number of kilometers per hour by 0.621371 to get miles per hour. The formula is shown in the "How it's calculated" section above.
Where does the conversion factor come from?
It's a published international standard. Most are defined exactly by international agreement (e.g. 1 inch = 25.4 mm exactly, 1 lb = 0.45359237 kg exactly). Source citations are listed under the formula above.