1 km = 0.621 miles · 1 mile = 1.609 km
Type in kilometres or miles and get the answer instantly — both directions. Useful for race entries, GPS unit mismatches, and training plan translations.
Kilometres
= Miles
Miles
= Kilometres
Quick Reference · Common Race Distances
| KM | MILES | RACE |
|---|---|---|
| 1.0 | 0.62 | 1 km |
| 5.0 | 3.11 | 5K |
| 10.0 | 6.21 | 10K |
| 21.097 | 13.11 | Half marathon |
| 42.195 | 26.22 | Marathon |
| 50.0 | 31.07 | 50K ultra |
| 100.0 | 62.14 | 100K ultra |
km ↔ miles — FAQ
Multiply the kilometres by 0.621371. For a quick mental estimate, take roughly 60% of the number: 10 km is about 6.2 miles. To go the other way, multiply miles by 1.609344.
A 5K is 3.11 miles (5 km × 0.621371).
A 10K is 6.21 miles.
A half marathon is 13.11 miles, or 21.0975 kilometres.
A marathon is 42.195 kilometres, which is 26.22 miles (commonly rounded to 26.2).
GPS error and your racing line both add distance: you rarely run the exact measured shortest path, so watches typically read 0.5–1% long. A marathon often shows 42.5–42.8 km on a watch even though the certified course is exactly 42.195 km.