Work out kilometres per hour to miles per hour instantly with clear inputs, formula shown and shareable results.
Converting Kilometres per hour to Miles per hour is one multiplication: a single km/h is 0.62137119 mph, so the amount is scaled by that factor. Reversing the direction divides by the same factor. The factor is an exact definition rather than a rounded figure, so the result stays precise at any magnitude. A mile is exactly 1,609.344 m, so the factor is exact: 100 km/h is 62.14 mph.
Kilometres per hour → Miles per hour
mph = km/h × 0.62137119
Miles per hour → Kilometres per hour
km/h = mph ÷ 0.62137119
One km/h equals 0.62137119 mph. That value is exact by definition.
Divide by 0.62137119 rather than multiplying, or flip the direction selector which does it for you.