The conversion factor
1 kilometer equals 0.621371 miles. Multiply your kilometers value by 0.621371 to get miles; divide to go back. For the reverse direction, use the miles to kilometers converter or the full length converter.
Where this conversion comes up
Mixing metric and imperial is a daily reality in travel, shipping, recipes, fitness apps, and spec sheets — this page gives the exact factor plus a scannable table for the values people actually need.