Kilometers are the distance unit on road signs, running courses and maps in nearly every country except the US and the UK. If you think in miles, this converter tells you how far a race, a hike or the next town really is — and the race table below covers the standard distances runners ask about most.
How to use the km to miles converter
- Type the distance in Kilometers (km).
- The answer appears in miles, with the same distance in feet and nautical miles below it.
- Further down you’ll find the steps, a kilometer-to-mile chart from 0.5 to 1,000 km, and the standard road-race distances in miles.
Kilometers to miles formula
Since 1959 the international mile has been exactly 1,609.344 meters. Dividing by 1.609344 is therefore the exact conversion:
Worked example: a 5K fun run
Step 1. 5 ÷ 1.609344 = 3.1069 miles.
Step 2. For the feet equivalent, 3.1069 × 5,280 = 16,404 ft.
Check. The mental estimate 5 × 5 ÷ 8 = 3.125 miles is within a few hundredths.
Applied to the marathon: 42.195 ÷ 1.609344 = 26.2188 miles. Runners who see “26.2” on a car sticker are reading a rounded version of that number.
Race distances in miles
| Race | Kilometers | Miles |
|---|---|---|
| 5K | 5 | 3.11 |
| 8K | 8 | 4.97 |
| 10K | 10 | 6.21 |
| 15K | 15 | 9.32 |
| Half marathon | 21.0975 | 13.11 |
| Marathon | 42.195 | 26.22 |
| 50K ultra | 50 | 31.07 |
| 100K ultra | 100 | 62.14 |
GPS watches often show a few hundredths more than these numbers at the finish, because runners rarely follow the shortest measured line around every bend. To turn a finish time into a per-mile pace, use the running pace calculator.
The Fibonacci shortcut
Consecutive Fibonacci numbers — 3, 5, 8, 13, 21, 34, 55 — have a ratio close to 1.618, which happens to be within about half a percent of 1.609. So any Fibonacci number of kilometers is roughly the previous Fibonacci number of miles:
| Kilometers | Fibonacci guess (mi) | Exact miles |
|---|---|---|
| 8 | 5 | 4.971 |
| 13 | 8 | 8.078 |
| 21 | 13 | 13.049 |
| 34 | 21 | 21.127 |
| 55 | 34 | 34.175 |
For other numbers, split them into Fibonacci pieces: 100 km = 89 + 8 + 3 km, which maps to 55 + 5 + 2 = 62 miles — against an exact 62.14.
Reading road signs abroad
Distances on European and Canadian signs are in kilometers, and so is the car’s trip computer in a rental car. Multiplying by 0.6 is a quick sanity check (it runs about 3.4% low), but if you are judging fuel range, use the exact answer: 300 km is 186.4 miles, not 180. The speed equivalent is on the km/h to mph converter. For the reverse direction, see miles to kilometers.
Frequently asked questions
How many miles is one kilometer?
One kilometer is 0.621371 miles. The exact relationship runs the other way: a mile is defined as 1.609344 km, so km ÷ 1.609344 gives miles with no rounding in the factor.
How many miles is a 5K and a 10K?
A 5K is 3.107 miles and a 10K is 6.214 miles. Race organizers usually shorten these to 3.1 and 6.2.
Why is a half marathon called 13.1 miles?
The half marathon is exactly 21.0975 km, half of the 42.195 km marathon. That converts to 13.109 miles, which is rounded to 13.1 on stickers and finisher medals. The full marathon is 26.219 miles, usually written 26.2.
How far is 100 km in miles?
100 km is 62.137 miles. That is also why a 100 km/h speed limit is about 62 mph.
What is the easiest way to estimate km to miles?
Multiply by 5 and divide by 8. Using 0.625 instead of 0.621371 makes the answer only about 0.6% high, so 40 km becomes 25 miles against an exact 24.85.