To convert km to miles, divide by 1.609344: the international mile is exactly 1,609.344 m, so 1 km ≈ 0.621371 mi. Formula: miles = km / 1.609344. For example, 5 km ≈ 3.107 mi and 10 km to miles is about 6.214 mi.
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How to use the km to miles converter
- Enter the distance in kilometers, for example 42.195.
- Read the km to miles converter result: 42.195 ÷ 1.609344 ≈ 26.219 mi.
- For a quick estimate, multiply kilometers by 0.6 and add a little.
What is the KM to miles formula?
miles = kilometers ÷ 1.609344 (≈ × 0.621371)
The reverse is kilometers = miles × 1.609344.
The inch, foot, yard and mile are defined exactly in meters (1 in = 2.54 cm, 1 ft = 0.3048 m, 1 yd = 0.9144 m, 1 mi = 1,609.344 m), so these factors are exact. The multiplier 0.621371 is rounded to six significant digits; the calculator uses the full-precision value.
What are kilometers and miles?
Length measures distance. The SI base unit is the meter. Since 1959 the international inch has been defined as exactly 2.54 cm, so the foot is exactly 0.3048 m and the mile exactly 1,609.344 m.
- Kilometer (km): 1 km = 1,000 m (Metric unit).
- Mile (mi): 1 mi = 1,609.344 m (US/Imperial unit).
Km to miles worked examples
- A 5K run: 5 ÷ 1.609344 = 3.10686 mi
- A marathon: 42.195 ÷ 1.609344 = 26.2188 mi
- A 100 km/h speed limit distance in one hour: 100 ÷ 1.609344 = 62.1371 mi
Conversion chart
| km | mi | km | mi |
|---|---|---|---|
| 1 | 0.6214 | 21.0975 | 13.1094 |
| 2 | 1.2427 | 25 | 15.5343 |
| 3 | 1.8641 | 42.195 | 26.2188 |
| 5 | 3.1069 | 50 | 31.0686 |
| 8 | 4.971 | 100 | 62.1371 |
| 10 | 6.2137 | 160 | 99.4194 |
| 15 | 9.3206 | 500 | 310.69 |
| 20 | 12.4274 | 1,000 | 621.37 |
Values are rounded to four decimal places, or two for results of 100 or more.
Quick mental conversion
Multiply by 0.6 for a quick estimate, or use Fibonacci numbers: 8 km ≈ 5 mi, 13 km ≈ 8 mi.
Race distances
| Race | Kilometers | 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 |
Kilometers from miles: reverse chart
Going the other way, kilometers = miles × 1.609344. Common values:
| miles | kilometers |
|---|---|
| 1 | 1.609344 |
| 2 | 3.218688 |
| 5 | 8.04672 |
| 10 | 16.09344 |
| 20 | 32.18688 |
| 50 | 80.4672 |
| 100 | 160.9344 |
| 500 | 804.672 |
| 1,000 | 1,609.344 |
Running pace and speed: per km to per mile
A pace per kilometer becomes a pace per mile by multiplying by 1.609344; speeds in km/h become mph by dividing by 1.609344:
| Pace per km | Pace per mile | Speed (km/h) | Speed (mph) |
|---|---|---|---|
| 4:00 | 6:26 | 15 | 9.32 |
| 4:30 | 7:15 | 13.33 | 8.28 |
| 5:00 | 8:03 | 12 | 7.46 |
| 5:30 | 8:51 | 10.91 | 6.78 |
| 6:00 | 9:39 | 10 | 6.21 |
| 7:00 | 11:16 | 8.57 | 5.33 |
Paces are rounded to the nearest second.
Kilometers to miles on the road
Speed limits convert the same way: 100 km/h ≈ 62.1 mph, 50 km/h ≈ 31.1 mph and 120 km/h ≈ 74.6 mph. The UK uses miles on road signs while most of the world uses kilometers. Use the miles to km converter for the reverse, the kph to mph converter for speeds and the pace calculator for race planning.
EV range and map scales
Electric car range is quoted in kilometers on the European WLTP cycle and in miles on the US EPA cycle. A WLTP range of 450 km is about 280 miles, but the EPA figure for the same car is usually lower because the test cycles differ. A km to miles conversion compares units, not test methods.
Map scales are another use. On a 1:50,000 map, 2 cm on paper is 1 km on the ground, or about 0.62 miles. Hikers planning a 12 km route can expect about 7.5 miles of walking.
Rental cars abroad show kilometers on the odometer, so a 300 km day trip means about 186 miles. Speed signs follow the same rule: 100 km/h is about 62 mph. A quick mental shortcut is to multiply by 0.6 and add a little, since the exact factor is 0.621371.
Running and cycling apps let you pick units, but shared routes often arrive in the other one. A 40 km bike ride is about 24.9 miles, and a 5 km parkrun is about 3.1 miles. If you train by heart rate or time rather than distance, the units matter less, but for comparing routes and race results it helps to convert first.
Related converters and calculators
Related conversions:
- Miles to km: mi to km
- kph to mph: speed
- Pace calculator: running pace
- Meters to feet: m to ft
- Speed converter: km/h and mph
Sources
NIST Special Publication 811, Appendix B; NIST: SI units – length.
Questions about this calculator
How many miles are in a km?
0.621371 mi.
How do I convert km to miles?
Divide by 1.609344. For example, 21.0975 km (half marathon) ≈ 13.109 mi.
What is 10 km in miles?
About 6.214 mi.
What is 5k in miles?
About 3.107 mi.
How do I convert pace per km to per mile?
Multiply by 1.609344: 5:00 per km ≈ 8:03 per mile.
Check the assumptions and units before relying on a result. Financial, tax and health estimates do not replace advice for your individual circumstances.
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