🏃 Distance & pace
km to miles Converter
Enter kilometres and press Convert to get miles. 10 km is 6.21 mi, and a marathon's 42.195 km is 26.22 mi.
About the km to miles Converter
A kilometre is 0.621371 miles because the mile was fixed at 1609.344 m. Race distances are where this conversion is checked most often: a 5K is 3.11 mi, a 10K is 6.21 mi, a half marathon is 13.11 mi and a full marathon is 26.22 mi — not the 26.0 the old name suggests.
For pace, 1 km is 0.621 mi, so a 5:00 min/km pace is 8:03 min/mile. Runners switching between the two usually keep both numbers handy rather than converting every split.
How the calculation works
- Miles = kilometres × 0.6213711922
- Kilometres = miles × 1.609344
- 1 km = 1000 m · 1 mile = 1609.344 m
Reference values
| Kilometres | Miles | Race |
|---|---|---|
| 1 km | 0.621 mi | Casual run |
| 5 km | 3.107 mi | Parkrun |
| 10 km | 6.214 mi | 10K |
| 21.097 km | 13.109 mi | Half marathon |
| 42.195 km | 26.219 mi | Marathon |
| 50 km | 31.069 mi | Ultra |
| 100 km | 62.137 mi | Centurion |
| 1 km | 0.621 mi | Pace: 5:00/km = 8:03/mi |
Worked examples
- 1 Kilometre = 0.621371 Mile.
- 2 Kilometre = 1.243 Mile.
- 5 Kilometre = 3.107 Mile.
- 10 Kilometre = 6.214 Mile.
- 50 Kilometre = 31.07 Mile.
- 100 Kilometre = 62.14 Mile.
Checking the answer
Multiply the Kilometre figure by 0.621371 to get Mile, and divide by the same number to come back. Twenty-five Kilometre should land at 15.53 Mile; an answer near 40.23 means the division went the wrong way. A quick sanity check is that Mile 6.214 must always be smaller than the matching Kilometre figure when the factor is above 1.
Common mistakes
- Treating a 10K as 6 miles exactly; it is 6.21.
- Converting pace from distance rather than from time per kilometre.
- Assuming a marathon is exactly 26 miles.
Using this conversion
The Kilometre to Mile relationship is fixed, so one factor covers every value you will enter: a household quantity and an industrial one behave identically. What changes with size is only how much the rounding matters, which is why the table above stops at a round number rather than at whatever figure you happen to need today.
When precision matters
For a rough Kilometre to Mile estimate one decimal place is plenty. For a contract, a shipping document or a lab result, keep the full figure from the converter and round only on the final line, so no intermediate step throws the Mile total out.
A last check on the numbers: 37 Kilometre works out to 22.99 Mile, and reversing that with the same factor brings you back to 37 Kilometre. Because Kilometre to Mile is a single multiplication, any tool that gives a different figure for the same input is rounding somewhere in the middle rather than only at the end.