How long is a half marathon
A half marathon is 13.1 miles, or 21.0975 kilometers, exactly half of the 26.2-mile marathon. This page puts that distance into familiar terms, shows how long it takes at common paces, and explains how to build up to it. The generator below makes a week-by-week plan for the distance.
How many miles is a half marathon, exactly
The exact figures are 13.109 miles and 21.0975 kilometers, which races round to 13.1 and 21.1. Other ways to picture it: just over four 5Ks, just over two 10Ks, or about 53 laps of a standard 400-meter track.
| Race | Miles | Kilometers |
|---|---|---|
| 5K | 3.107 | 5 |
| 10K | 6.214 | 10 |
| Half | 13.109 | 21.0975 |
| Marathon | 26.219 | 42.195 |
Course measurers follow the shortest legal path around every bend, so a GPS watch usually shows a little more than 13.1 at the finish; you ran the corners wide, the course did not grow.
Build your free half marathon plan
Same engine as every plan on this site, but with your race date, your run days and your longest recent run. Prints to PDF, exports to your calendar. No signup.
Half marathon in km and miles on the course
Races in the United States mark every mile; most races elsewhere mark every kilometer, and many big-city events mark both. Expect the finish line to come a tenth of a mile after the 13-mile marker, or just under a hundred meters after the 21 km sign. If your watch is set to one unit and the course to the other, write the key splits in both on your hand. The halfway point, the 10K mark and the final mile are enough.
Treadmills and running apps count in whichever unit you choose, so a 21.1 km treadmill session and a 13.1-mile one are the same workout. The pace calculator converts a pace from one unit to the other.
How far is a half marathon in time, at your pace
Multiply your pace by 13.109 miles. The rows below are computed from the exact distance; the pace chart for the half has every finish time from one hour up.
| Pace per mile | Pace per km | Finish |
|---|---|---|
| 8:00 | 4:58 | 1:44:53 |
| 9:00 | 5:36 | 1:57:59 |
| 10:00 | 6:13 | 2:11:06 |
| 12:00 | 7:27 | 2:37:19 |
Two hours is the round target many runners aim at; how long it takes you is covered in the finish-time guide.
Half vs full marathon: half the miles, not half the training
A marathon is 26.219 miles, so the half is precisely half the distance, but the preparation is not half the work. A first half needs a long run of about 10 to 12 miles and roughly 10 to 12 weeks. A marathon needs a long run near 20 miles and 16 weeks or more. Fueling during the race also becomes necessary rather than optional. That is why the half is the usual first long race.
How to build up to 13.1 miles
Three or four runs a week, one of them a long run that grows a little each week. It reaches 10 to 12 miles about two weekends before the race, and a short taper follows. The 12-week plan lays this out day by day, and the couch-to-half schedule starts from no running at all. The generator rebuilds either around your own race date, run days and longest recent run. The long run is capped at 14 miles in every half plan it produces.
Frequently asked questions
How many km is a half marathon?
21.0975 kilometers, usually written as 21.1 km.
Is a half marathon 13 miles or 13.1?
13.1 miles, or 13.109 to three decimals. The extra tenth is the same rounding as the marathon's 26.2.
How many miles is half marathon in laps of a track?
About 53 laps of a 400-meter track. Nobody races it that way, but it is a useful picture of the distance.
How many miles in a marathon and a half marathon?
26.2 miles for the marathon and 13.1 for the half. In kilometers, 42.195 and 21.0975.
How long is a half marathon compared to a 10K?
Just over twice as long: 21.0975 km against 10 km, or 13.1 miles against 6.2.