Kilometers to Miles Converter
Convert kilometers to miles instantly. 1 km = 0.621371 mi. Formula, a quick reference table and why the factor never rounds evenly.
Written by Rahman · Last reviewed
Quick answer
One kilometer equals 0.621371 miles. Multiply a distance in kilometers by 0.621371 (or divide by 1.609344) to get miles, so 10 km is 6.21 miles and a 100 km/h speed limit is about 62 mph.
| Metre (m) | 1000 |
| Kilometre (km) | 1 |
| Decimetre (dm) | 10000 |
| Centimetre (cm) | 100000 |
| Millimetre (mm) | 1000000 |
| Micrometre (µm) | 1000000000 |
| Nanometre (nm) | 1.000000000e+12 |
| Mile (mi) | 0.6213711922 |
| Yard (yd) | 1093.613298 |
| Foot (ft) | 3280.839895 |
| Inch (in) | 39370.07874 |
| Nautical mile (nmi) | 0.5399568035 |
| Light year (ly) | 1.057001e-13 |
km to mi conversion table
| km | mi |
|---|---|
| 1 km | 0.6213711922 mi |
| 2 km | 1.242742384 mi |
| 3 km | 1.864113577 mi |
| 4 km | 2.485484769 mi |
| 5 km | 3.106855961 mi |
| 6 km | 3.728227153 mi |
| 7 km | 4.349598346 mi |
| 8 km | 4.970969538 mi |
| 9 km | 5.59234073 mi |
| 10 km | 6.213711922 mi |
| 20 km | 12.42742384 mi |
| 30 km | 18.64113577 mi |
| 40 km | 24.85484769 mi |
| 50 km | 31.06855961 mi |
| 60 km | 37.28227153 mi |
| 70 km | 43.49598346 mi |
| 80 km | 49.70969538 mi |
| 90 km | 55.9234073 mi |
| 100 km | 62.13711922 mi |
| 250 km | 155.3427981 mi |
| 500 km | 310.6855961 mi |
| 1000 km | 621.3711922 mi |
How to convert km to mi
A marathon is defined as exactly 42.195 kilometers, fixed by the International Amateur Athletic Federation in 1921 to match the 1908 London Olympics course. Converted, that is 26.2187 miles, which is why English-language race commentary rounds it to "26.2" rather than a neater-looking number: the distance was set in kilometers first, and the mile figure is simply what falls out of the conversion.
The factor is irrational-looking (0.621371…) because it comes from the international yard-and-pound agreement of 1959, which fixed the mile at exactly 1,609.344 metres: a metric definition of an imperial unit. There is no version of this conversion that resolves to a clean fraction; 0.621371 is already rounded to six significant figures, which is precise enough for anything short of surveying.
Frequently Asked Questions
How many miles is 5 km?
⌄
5 km is 3.107 miles, which is why a "5K" road race is commonly described as roughly 3.1 miles.
Is a kilometer longer than a mile?
⌄
No. A mile (1.609 km) is longer than a kilometer, so a given number of kilometers is always a smaller number of miles.