How Many Miles Is a 5K? (Plus 10K, Half, and Marathon)
The short answer: a 5K is 3.1 miles
A 5K is 3.1 miles — more precisely, 3.10686 miles. The “5K” simply means 5 kilometres, and since one kilometre equals 0.621371 miles, five of them come to just over 3.1 miles. On a standard 400-metre running track, that’s 12.5 laps.
That’s the whole answer to the headline question. But “5K” is only one of a handful of standard race distances, and runners constantly need to convert between kilometres and miles for all of them. Here’s the complete reference.
Common race distances in miles and kilometres
| Race | Kilometres | Miles | Track laps (400m) |
|---|---|---|---|
| 5K | 5 km | 3.11 mi | 12.5 |
| 10K | 10 km | 6.21 mi | 25 |
| 15K | 15 km | 9.32 mi | 37.5 |
| Half marathon | 21.0975 km | 13.11 mi | 52.7 |
| Marathon | 42.195 km | 26.22 mi | 105.5 |
The two long-distance figures are the ones people misremember most. A half marathon is 13.1 miles, not 13 even, and a full marathon is 26.2 miles — that famous “point two” is why the distance feels longer than the round number suggests. The marathon’s oddly specific length traces back to the 1908 London Olympics, where the course was set at 26 miles 385 yards so it could finish in front of the royal box.
Why kilometres and miles both stick around
Most of the world measures running in kilometres. The United States and the United Kingdom hold onto miles for everyday distances, even though UK road signs and US track events use a mix. Race distances are almost always defined in kilometres or metres — a “5K” is exactly 5,000 metres by definition — and then converted to miles for the runners who think that way. The conversion to keep in your head: 1 mile = 1.609 kilometres, or equivalently, 1 km = 0.621 miles.
This is also why your finish-line splits can feel confusing. If your watch is set to miles but the race posts kilometre markers, you’ll pass a clock at every 0.62 of your own mile count. The Pace Calculator converts between the two instantly, and the Running Pace Chart lays out paces in both units side by side.
How long does each distance take?
Distance is fixed; time depends on you. As a rough orientation for a recreational runner:
- 5K (3.1 mi): most first-timers finish between 28 and 37 minutes; a 10:00/mile pace gives 31:04.
- 10K (6.2 mi): commonly 55 minutes to 1:10 for newer runners.
- Half marathon (13.1 mi): the average is around 2:00–2:20.
- Marathon (26.2 mi): the global average is about 4 hours 32 minutes.
To turn your own recent race into a prediction for a different distance, use the Race Time Predictor — enter a 5K time and it estimates your 10K, half, and marathon. And if you’re converting daily activity rather than races, a 5K works out to roughly 4,800 running steps or about 7,000 walking steps; the Steps to Miles Calculator handles any step count.
Which distance should you start with?
The 5K is the most popular race distance in the world for a reason: it’s long enough to feel like an accomplishment, short enough to train for in a couple of months, and forgiving enough that walking part of it is completely normal. If you’re new, the Couch to 5K Plan gets most people from the sofa to the finish line in nine weeks. From there the 5K Training Plan sharpens your time, and the half marathon and marathon plans are waiting when you want to go longer.
Want race predictions, pace math, and training paces in your pocket? Pacesmith is a $1.99 iOS app — no subscription, no account, works offline.