Convert kilometers to miles instantly. Free online km to mi converter with accurate results and formula explanation.
Formula
mi = km × 0.621371The kilometer (km) is a metric unit of length used worldwide, while the mile (mi) is an imperial unit primarily used in the United States, United Kingdom, and a few other countries. Converting between kilometers and miles is essential for international travel, understanding speed limits, and comparing distances.
mi = km × 0.621371To convert kilometers to miles, multiply by 0.621371. This factor comes from the definition 1 mile = 1.609344 km, making 1 km = 1/1.609344 ≈ 0.621371 miles.
| Input | Output |
|---|---|
| 1 km | 0.621371 mi |
| 5 km | 3.10686 mi |
| 10 km | 6.21371 mi |
| 100 km | 62.1371 mi |
| 42.195 km | 26.2188 mi (marathon) |