About this tool
Enter kilometers to see miles, or enter miles to see kilometers. The converter uses the exact definition of the international mile, 1 mile = 1.609344 km, so 1 km is about 0.621371 miles. It runs in your browser and nothing is sent anywhere.
How to use it
Type a distance in the left box and the mile value appears on the right. Decimals are fine, so 7.5 km works. To go the other way, type in the miles box. Speeds convert with the same factor, so km/h to mph is the same calculation, and the speed table below lists common road limits.
How to convert km to miles by hand
Multiply kilometers by 0.621371. For a quick estimate, multiply by 0.6 and add a little: 100 km times 0.6 is 60, and the exact answer is 62.14 miles. Another trick is to take half the kilometers and add a tenth of that half. It is close enough for road signs and running plans.
Kilometers to miles reference table
| Kilometers | Miles |
|---|---|
| 1 km | 0.62 miles |
| 3 km | 1.86 miles |
| 5 km (5K) | 3.11 miles |
| 10 km (10K) | 6.21 miles |
| 21.0975 km (half marathon) | 13.11 miles |
| 42.195 km (marathon) | 26.22 miles |
| 50 km | 31.07 miles |
| 100 km | 62.14 miles |
Race distances
The 5K is 3.11 miles and the 10K is 6.21 miles. A half marathon is 13.11 miles and a full marathon is 26.22 miles (the official figure is 26 miles 385 yards). Runners often round 5K to 3.1 miles, which is accurate enough for planning a pace.
Speed limits: km/h to mph
| Speed | Miles per hour |
|---|---|
| 30 km/h | 18.6 mph |
| 50 km/h | 31.1 mph |
| 60 km/h | 37.3 mph |
| 80 km/h | 49.7 mph |
| 100 km/h | 62.1 mph |
| 120 km/h | 74.6 mph |
Where people need km to miles
- Travel and driving: road signs in Canada, Europe and most of the world use kilometers, while US car dashboards and maps often use miles.
- Running and cycling: training plans, race entries and watch settings switch between the two units.
- Fuel and car specs: distance per tank and service intervals are quoted in either unit.
- Maps and fitness apps: exported tracks can use the unit of the app that recorded them.
Things to watch out for
A mile is longer than a kilometer, so the mile number is always smaller: 10 km is only 6.2 miles. Do not mix the international mile with the nautical mile (1.852 km), which is used at sea and in aviation. Also remember that speed conversions assume the same factor, so 100 km/h is 62.1 mph, not 100 mph.
Frequently asked questions
1 kilometer is about 0.621371 miles. The exact definition is 1 mile = 1.609344 km, so you divide kilometers by 1.609344 to get miles.
5 km is 3.11 miles. That is why a 5K race is often described as 3.1 miles.
Yes. The factor is identical because both units are per hour. 100 km/h equals 62.1 mph.