To convert kilometers to miles, divide by 1.609344 (or multiply by about 0.621371). A 5K race is 3.11 miles, a 10K is 6.21 miles, and 100 km is 62.14 miles.
Kilometers are used on road signs in Canada, Europe, Australia and most other countries, and in almost every running race.
How to use the km to miles converter
- Type the value in kilometers into the box. Decimals are fine.
- The result in miles updates as you type, along with the working.
- Need the other way? Switch the direction menu, or open the miles to km converter.
Formula
A statute mile is 5,280 ft, and because the foot is exactly 0.3048 m, a mile is exactly 1,609.344 m, or 1.609344 km. A nautical mile (1.852 km) is a different unit used at sea and in aviation.
Worked example
How many miles is a 5K?
- 5 ÷ 1.609344 = 3.10686.
- Result: 3.11 miles.
For a full marathon: 42.195 ÷ 1.609344 = 26.2188 mi. To turn a race time into a per-mile pace, use the pace calculator.
Kilometers to miles chart
Common values, rounded to 4 decimal places.
| Kilometers (km) | Miles (mi) |
|---|---|
| 1 km | 0.6214 mi |
| 2 km | 1.2427 mi |
| 3 km | 1.8641 mi |
| 5 km | 3.1069 mi |
| 8 km | 4.971 mi |
| 10 km | 6.2137 mi |
| 15 km | 9.3206 mi |
| 20 km | 12.4274 mi |
| 21.0975 km | 13.1094 mi |
| 25 km | 15.5343 mi |
| 42.195 km | 26.2188 mi |
| 50 km | 31.0686 mi |
| 80 km | 49.7097 mi |
| 100 km | 62.1371 mi |
| 160 km | 99.4194 mi |
| 500 km | 310.6856 mi |
| 1,000 km | 621.3712 mi |
Where kilometers are used
- Races: 5K, 10K, half marathon (21.0975 km) and marathon (42.195 km).
- Driving abroad: distance signs and rental-car odometers in metric countries.
- Hiking and cycling apps: most can be set to either, but GPX files and many trail guides use km.
Quick mental math
Multiply by 6 and divide by 10, then add a bit: 10 km × 0.6 = 6, plus 0.2 ≈ 6.2 mi. The Fibonacci trick works backwards too: 8 km ≈ 5 mi, 13 km ≈ 8 mi.
Related conversions
Going the other way: miles to km converter. Related pages: inches to cm converter, cm to inches converter, feet to meters converter. For other units in the same family, use the full length converter or the pace calculator.
Caveats and assumptions
- Results show up to 10 significant digits; the chart is rounded for reading. Keep full precision for engineering, medical or legal work.
Frequently asked questions
How many miles is 1 km?
About 0.621371 miles.
How many miles is a 10K?
6.2137 miles.
Is a kilometer longer than a mile?
No. A mile is about 1.6 times as long as a kilometer.
How many miles is 100 km?
62.137 miles. A 100 km/h speed limit is 62.1 mph; see km/h to mph converter.
Sources
- NIST — SI Units: Length (1959 definition of the inch) — 1 in = 25.4 mm exactly
- NIST SP 811 Appendix B.9 — Conversion factors — mile (international) to meter
This calculator gives estimates for planning and education. Check measurements, local codes, supplier specs and your school's official policy before relying on a result. See our disclaimer and how we build and check calculators.