Quick answer: a 5K is 3.107 miles (usually rounded to 3.1), a 10K is 6.214 miles, a half marathon is 13.109 miles (21.0975 km) and a marathon is 26.219 miles (42.195 km). A mile is exactly 1,609.344 m, a little over four laps of a 400 m track.
How to use the converter
Type a number, choose its unit and read the result in every other unit at once. Enter 3 with kilometres for a 3K, 400 with metres for one lap, or 26.2 with miles to see a marathon in kilometres. When the distance matches a standard race within half a percent, the race name appears next to the result. The lap count assumes the inside lane of a standard outdoor track.
Where the exact numbers come from
The yard is defined as exactly 0.9144 m, so a mile of 1,760 yards is exactly 1,609.344 m; NIST lists both values in its conversion tables. On the road, World Athletics rules fix the marathon at 42.195 km, and the half marathon is half of that, 21.0975 km. Metric races (5K, 10K and so on) are whole kilometres, so their mile figures are simply the metres divided by 1,609.344.
Worked examples
8K to miles: 8,000 / 1,609.344 = 4.971 miles, just short of 5 miles, and exactly 20 laps of a track. 3K to miles: 3,000 / 1,609.344 = 1.864 miles. 400 m to miles: 400 / 1,609.344 = 0.2485 miles, about a quarter mile. Four laps (1,600 m) leave you 9.344 m short of a full mile, which is why a track mile starts a little behind the usual finish line. The marathon is often described as 26 miles 385 yards; that works out to 42,194.988 m, about a centimetre short of 42.195 km.
Standard race distances
Track events, road races and ultras, from the 100 m dash to 100 miles. Laps are for lane 1 of a 400 m track.
| Race | Km | Miles | Yards | 400 m laps |
|---|---|---|---|---|
| 100 m | 0.100 | 0.062 | 109.4 | 0.25 |
| 200 m | 0.200 | 0.124 | 218.7 | 0.50 |
| 400 m | 0.400 | 0.249 | 437.4 | 1.00 |
| 800 m | 0.800 | 0.497 | 874.9 | 2.00 |
| 1500 m | 1.500 | 0.932 | 1,640.4 | 3.75 |
| Mile | 1.609 | 1.000 | 1,760.0 | 4.02 |
| 3K (3000 m) | 3.000 | 1.864 | 3,280.8 | 7.50 |
| 2 miles | 3.219 | 2.000 | 3,520.0 | 8.05 |
| 5K | 5.000 | 3.107 | 5,468.1 | 12.50 |
| 8K | 8.000 | 4.971 | 8,748.9 | 20.00 |
| 5 miles | 8.047 | 5.000 | 8,800.0 | 20.12 |
| 10K | 10.000 | 6.214 | 10,936.1 | 25.00 |
| 12K | 12.000 | 7.456 | 13,123.4 | 30.00 |
| 15K | 15.000 | 9.321 | 16,404.2 | 37.50 |
| 10 miles | 16.093 | 10.000 | 17,600.0 | 40.23 |
| 20K | 20.000 | 12.427 | 21,872.3 | 50.00 |
| Half marathon | 21.098 | 13.109 | 23,072.5 | 52.74 |
| 25K | 25.000 | 15.534 | 27,340.3 | 62.50 |
| 30K | 30.000 | 18.641 | 32,808.4 | 75.00 |
| Marathon | 42.195 | 26.219 | 46,145.0 | 105.49 |
| 50K | 50.000 | 31.069 | 54,680.7 | 125.00 |
| 50 miles | 80.467 | 50.000 | 88,000.0 | 201.17 |
| 100K | 100.000 | 62.137 | 109,361.3 | 250.00 |
| 100 miles | 160.934 | 100.000 | 176,000.0 | 402.34 |
Good to know
- World Athletics rules measure a road course along the shortest possible route a runner could follow within the permitted road. A GPS watch records the line you actually ran, so its total rarely matches the race distance exactly.
- Outer lanes are longer than lane 1: one lap in lane 2 is about 407.04 m, calculated from the World Athletics marking rules.
- Rounding adds up: a marathon run at a "per 26.2 miles" pace is 42,164.8 m, about 30.2 m short of the real distance.
Know the distance, now find the pace: use the pace calculator, switch min/mile to min/km on the pace converter, or see lap times on the track pace chart. To turn a step count into miles, use the steps to miles calculator.
Sources: NIST Special Publication 811, Appendix B.9: conversion factors (mile 1.609 344 E+03 m; yard 9.144 E-01 m); World Athletics Technical Rules, Book C2.1, Rule 55 road race distances (Marathon 42.195 km). Rules checked . Found a problem? Tell us.
Questions
How long is a 5K in miles?
A 5K is 5,000 m, which is 3.107 miles. Most runners round it to 3.1 miles. On a track it is 12.5 laps of lane 1.
How many miles is a half marathon?
A half marathon is 21.0975 km, or 13.109 miles, usually written as 13.1 miles.
How many miles is a marathon?
A marathon is 42.195 km, which is 26.219 miles, usually written as 26.2 miles.
How far are 3K, 8K and 400m in miles?
3K is 1.864 miles, 8K is 4.971 miles and 400 m is 0.2485 miles, just under a quarter mile.
How many laps of a track is a mile?
A mile is 4.02 laps of a 400 m track in lane 1: four full laps plus 9.344 m.