Kilometers to Miles Converter (km to mi)

How to use this calculator: km to miles

1. 1Enter the value measured in kilometer (km).
2. 2Confirm the direction is Kilometer (km) to Mile (mi); reversing the units changes the factor or offset.
3. 3Apply mi = km × 0.62137119. The live converter performs this substitution as you type.
4. 4Read the answer in mi and keep only justified precision.

Conversion formula

One mile equals 1.609344 kilometers, so kilometers convert to miles by dividing by 1.609344. Runners often need it for 5K, 10K, half marathon (21.0975 km) and marathon (42.195 km) distances.

The units measure the same quantity at different scales: 1 km = 0.62137119 mi, and 1 mi = 1.609344 km.

Worked conversion example: Kilometers to Miles

1. Given: 15 km
2. Substitute: mi = 15 × 0.62137119 = 9.32056788
3. Result: 15 km = 9.32056788 mi

Accuracy checklist

The converter keeps extra precision internally. Report only the precision supported by the original measurement and follow the required rounding rule.

Direction check: a smaller unit usually gives a larger number; temperature is an exception.

Unit definitions and SI traceability: NIST Office of Weights and Measures — SI Units.