How do I convert km to miles?
Since 1 mile is defined as exactly 1.609344 kilometres, converting kilometres to miles means dividing by 1.609344, or multiplying by 0.621371. For example, a 10 km run is about 6.21 miles, and a marathon of 42.195 km is 26.22 miles. Enter any distance in FixDoks's KM to Miles converter to get the exact result and a running-distance chart.
KM to Miles at a glance
| Formula | miles = kilometres x 0.621371 |
|---|---|
| Example | 10 km = 6.21 miles |
| Processing | In your browser; your files are not uploaded |
| Price | Free |
| Works on | Chrome, Edge, Safari and Firefox on Windows, Mac, Android and iPhone |
How to use KM to Miles Converter
- Type the distance in kilometres.
- Read the distance in miles instantly.
- Tap ⇄ to convert miles to kilometres.
How do I convert km to miles?
An international mile is exactly 1,609.344 metres. So:
miles = kilometres ÷ 1.609344, which is the same as miles = kilometres × 0.621371
Worked examples
- 10 km × 0.621371 = 6.21 miles
- A half marathon of 21.0975 km is 13.11 miles
- A full marathon of 42.195 km is 26.22 miles
- Delhi to Agra by expressway is roughly 230 km, which is about 143 miles
Quick mental method
Multiply by 6 and divide by 10. 50 km × 6 = 300, ÷ 10 = 30 miles (exact 31.07). To go from miles to km, multiply by 8 and divide by 5: 30 miles becomes 48 km (exact 48.28). A neat trick: consecutive Fibonacci numbers are close to the km-mile ratio, so 5 miles is about 8 km, 8 miles about 13 km, and 13 miles about 21 km.
Speed: km/h and mph
The same factor converts speeds. 100 km/h is 62.1 mph and 60 mph is 96.6 km/h. Speed limits on Indian expressways are in km/h. The UK and the US use mph. If you rent a car abroad, check which unit the speedometer uses. You can convert speeds directly in the Unit Converter by choosing Speed.
Running distances
| Race | Kilometres | Miles |
|---|---|---|
| 5K | 5 | 3.11 |
| 10K | 10 | 6.21 |
| Half marathon | 21.0975 | 13.11 |
| Marathon | 42.195 | 26.22 |
| 50K ultra | 50 | 31.07 |
Running apps let you pick km or miles. Pace converts too: a pace of 6 minutes per km equals about 9 minutes 39 seconds per mile.
How do I convert miles back to km?
Multiply miles by 1.609344. A 3 mile walk is 4.83 km, a 100 mile drive is 160.9 km and a 26.2 mile marathon is 42.2 km. Use the swap button to convert in that direction and the table updates to match.
Fuel economy
Car mileage in India is quoted in km per litre, while the US uses miles per US gallon. 1 km/l is about 2.35 mpg (US), so a car that gives 18 km/l does about 42 mpg. The UK uses the larger imperial gallon, where 1 km/l is about 2.82 mpg.
Nautical miles
Ships and aircraft use the nautical mile, which is 1,852 m, or about 1.15 ordinary miles. Speeds in nautical miles per hour are called knots. Both are available in the Unit Converter.
The mile used in the UK and US today is the international mile, defined in 1959. The old US survey mile differs by about 3 mm per mile and is no longer used for new work.