How Many Miles Is a 5K, 10K, Half Marathon and Marathon?

The short answer

A 5K is 3.1 miles. A 10K is 6.2 miles. A half marathon is 13.1 miles. A marathon is 26.2 miles. Those are the rounded figures everyone uses; the exact ones are 3.107, 6.214, 13.109 and 26.219.

Race distances are set in metric because athletics is governed internationally, so the mile figures are always conversions rather than the official number. Our miles vs kilometers guide has the arithmetic and the pace conversions.

Every distance at a glance

Those times assume an even pace from start to finish, which almost nobody holds — especially over a half or a full. Treat them as the arithmetic rather than a prediction.

The 5K: 3.1 miles

Five kilometers, 3.107 miles, 5,000 metres. It is the most-run race distance in the world and the one essentially every beginner plan ends at, because it is long enough to need training and short enough that nine weeks of it is realistic.

The NHS Couch to 5K plan runs nine weeks of run/walk intervals, three sessions a week, finishing at 30 minutes of continuous running — which for most people is roughly the 5K distance. You need one pair of shoes and nothing else.

The 10K: 6.2 miles

Ten kilometers, 6.214 miles. Double the 5K, and the first distance where pacing becomes a skill rather than an afterthought — go out at 5K effort and the last two miles will teach you something.

Hal Higdon's Novice 10K is eight weeks with the weekend run building from 3 to 5.5 miles. Our how long to train for a 10K guide covers the timeline from wherever you are starting.

The half marathon: 13.1 miles

21.0975 km, 13.109 miles. Not a round number in either system, because it is simply half of the marathon distance — which is itself an accident of history rather than a design.

Higdon's Novice 1 Half is twelve weeks, with the long run building to 10 miles. This is the distance where a second pair of shoes starts to make sense and where what you eat and drink during the race becomes a real variable — our first half marathon tips covers both.

The marathon: 26.2 miles

42.195 km, 26.219 miles. The oddly specific distance was fixed at the 1908 London Olympics and has been the standard ever since.

Higdon's Novice 1 Marathon is eighteen weeks and peaks at a 20-mile long run — note that the plan never has you run the full distance in training. At this volume shoes become a rotation rather than a pair; marathon training mileage and shoe rotation explains why.

What you need at each distance

Not sure which distance to aim at? Our pace and mileage finder matches shoes to the week you actually run, and the Couch to 5K gear checklist covers the full starting kit in order of spend.