Last updated: September 2026
Length conversion
Kilometers to Miles (km to mi)
Helpful for interpreting metric road signs, running distances, and trip plans in places that use miles.
1 km
0.621371192237 mi
mi = km ÷ 1.609344
The formula
How to convert kilometers to miles
Apply mi = km ÷ 1.609344. For example, 1 km equals 0.621371192237 mi.
Precision
Accurate constants, readable results
OmniUnit calculates with the full stored conversion factor, then displays up to 12 significant digits.
Common kilometers conversions
| Kilometers | Miles |
|---|---|
| 1 km | 0.621371192237 mi |
| 5 km | 3.10685596119 mi |
| 10 km | 6.21371192237 mi |
| 21.1 km | 13.1109321562 mi |
| 42.195 km | 26.2187574565 mi |
| 100 km | 62.1371192237 mi |
Related length conversions
Frequently asked questions
How many miles are in 1 kilometer?
One kilometer equals 0.621371192237 miles. The mile is defined as exactly 1.609344 kilometers, so one kilometer is 1 ÷ 1.609344 miles, which is 0.621371192237.
How many kilometers are in 1 mile?
One mile equals exactly 1.609344 kilometers, by international definition. To convert miles back to kilometers, use the miles-to-kilometers page, which shows the exact formula and a quick calculator.
How do I convert kilometers to miles without a calculator?
Multiply the kilometers by 0.621 for a quick estimate — for example, 100 km is about 62.1 miles. For precise results, use the calculator above.
Is the kilometer-to-mile conversion exact?
Yes. The international mile is defined as exactly 1.609344 kilometers, so 1 km = 0.621371192237 mi is a fixed definition, not a measurement. OmniUnit calculates with the full stored factor for maximum precision.