Kilometers to Miles Converter
Convert km to miles instantly — exact, free, and no sign-up required.
Runs entirely in your browser — nothing you type is uploaded or stored.
How to convert kilometers to miles
To convert kilometers to miles, multiply the number of kilometers by 0.621371. This comes from the exact definition of the mile as 1,609.344 metres (fixed by international agreement in 1959), so 1 kilometre equals 1000 ÷ 1609.344 = 0.62137119… miles. The factor is irrational when carried far enough, which is why every published conversion is itself a rounded approximation — the calculator above carries it to 8 significant figures rather than the 2–3 you'll find in a rule-of-thumb table.
Worked example: converting a race distance
A half marathon is defined as 21.0975 km. Enter that into the "From" box above and you'll get 13.1094 miles — matching the commonly quoted "13.1 miles" figure runners use, but to full precision. For a full marathon (42.195 km), the result is 26.2188 miles, the source of the familiar "26.2" shorthand.
Common mistake: confusing statute miles with nautical miles
The "miles" in this conversion are statute miles (1609.344 m), the ones used for road distances and race lengths. Nautical miles — used in aviation and marine navigation — are a different, longer unit (1852 m exactly). If you're converting a flight or shipping distance, switch the "To" unit to "Nautical miles (nmi)" under the Length category instead; mixing the two up by even a small distance adds up over a long route.
Quick reference
| Kilometers | Miles |
|---|---|
| 1 km | 0.6214 mi |
| 5 km | 3.1069 mi |
| 10 km | 6.2137 mi |
| 21.1 km (half marathon) | 13.11 mi |
| 42.2 km (marathon) | 26.22 mi |
| 100 km | 62.14 mi |
Need the reverse? Use the swap button above to switch to miles → kilometers instantly, or type your value straight into the "To" box.
How to use the converter
Three steps. No account, no download, no waiting.
Confirm the units
This page is pre-set to km to miles. Change either dropdown any time to switch units or category — every other EngiConvert category is available from the same selector.
Enter your value
Type a number into the "From" box. The result updates instantly as you type — no button to press.
Copy your result
Use the swap button to flip the conversion, or hit "Copy result" to grab the converted value.
Frequently asked questions
How many miles is 1 km?
1 kilometer equals 0.621371 miles.
How do I convert km to miles quickly in my head?
A rough estimate: multiply kilometers by 0.62, or divide by 1.6. For an exact figure, use the calculator above.
Is a mile longer than a kilometer?
Yes. A mile (1.609 km) is longer than a kilometer, so a distance in miles is always a smaller number than the same distance in kilometers.
Why do UK road signs use miles when the rest of Europe uses km?
The UK retains miles and yards for road signage by long-standing legal convention (the Weights and Measures Act), even though most other measurements in the UK, including fuel sold by the litre, are metric — a split that trips up a lot of visitors.
More conversions
Every category is available in the full converter