Km to Miles Converter

Convert kilometres to miles and back instantly. Enter any value, pick a direction and the result updates live.

Enter a value above to convert

How the km to miles conversion works

Kilometres to Miles
miles = km × 0.621371
Example: 10 km × 0.621371 = 6.21 miles. A 5 km run is about 3.11 miles.
Miles to Kilometres
km = miles × 1.60934
Example: 5 miles × 1.60934 = 8.05 km. A 26.2 mile marathon is about 42.2 km.

1 kilometre = 0.621371 miles and 1 mile = 1.60934 kilometres. The two factors are reciprocals of each other (1 ÷ 0.621371 ≈ 1.60934), so converting one way and back returns the original value.

Km to miles conversion chart

Common distances including the 5K, 10K, half marathon (21.1 km) and full marathon (42.2 km), rounded to two decimal places.

KilometresMiles
1 km0.62 mi
2 km1.24 mi
3 km1.86 mi
5 km (5K)3.11 mi
10 km (10K)6.21 mi
15 km9.32 mi
20 km12.43 mi
21.1 km (half marathon)13.11 mi
25 km15.53 mi
42.2 km (marathon)26.22 mi
50 km31.07 mi
100 km62.14 mi

Miles to km conversion chart

Common mileage values converted to kilometres, rounded to two decimal places.

MilesKilometres
1 mi1.61 km
2 mi3.22 km
3 mi4.83 km
5 mi8.05 km
10 mi16.09 km
13.1 mi (half marathon)21.08 km
15 mi24.14 km
20 mi32.19 km
26.2 mi (marathon)42.16 km
30 mi48.28 km
50 mi80.47 km
100 mi160.93 km

Frequently asked questions

How many miles in a km?

One kilometre equals 0.621371 miles, or roughly 0.62 miles. So a kilometre is a little under two-thirds of a mile. To convert any number of kilometres to miles, multiply by 0.621371.

How many km in a mile?

One mile equals 1.60934 kilometres, or roughly 1.61 km. To convert miles to kilometres, multiply the number of miles by 1.60934. For a quick mental estimate, multiply by 1.6.

How do I quickly estimate km to miles in my head?

A simple trick is to multiply kilometres by 0.6 (or take roughly five-eighths of the value). For example, 10 km ≈ 6 miles and 100 km ≈ 62 miles. It is slightly low but close enough for everyday estimates.

How many miles is a 5K, 10K and a marathon?

A 5K is 5 km ≈ 3.11 miles, a 10K is 10 km ≈ 6.21 miles, a half marathon is 21.1 km ≈ 13.11 miles, and a full marathon is 42.2 km ≈ 26.22 miles.

Why are the conversion factors 0.621371 and 1.60934?

These come from the international definition of a mile as exactly 1,609.344 metres. Dividing 1 km (1,000 m) by that gives 0.621371 miles per km, and the reciprocal gives 1.60934 km per mile.