How many miles is a half marathon?

A half marathon sits in a sweet spot. It's twice as far as a 10K and long enough to feel like a real endurance event, yet short enough that a working adult can get ready for one in about three months. That might be why it draws so many more runners than the full marathon. In Swiss races from 1999 to 2014, Knechtle and colleagues (2016) counted 7.5 times as many men and 12.3 times as many women finishing half marathons as marathons.

If you've just signed up for your first one, though, 13.1 can look like a number from somebody else's life. The usual worry is being the slowest person out there, or getting halfway through training and quietly letting the plan slide. Knowing what a normal half marathon looks like, in miles and in hours, takes a lot of that fear out of it.

This page answers how many miles a half marathon is and how long a half marathon takes for an average runner. It also covers how times change with age and sex, whether 2 hours is a good time, what your 10K says about your half, and how long walking one takes.

How Long Is a Half Marathon?

A half marathon is 13.1 miles long, or 21.1 kilometers. To be exact, it's 21,097.5 meters, which is 13.109 miles or 13 miles and 192.5 yards. That odd figure comes straight from the full marathon. When the marathon was fixed at 42.195 kilometers in 1921, half of it became 21.0975, and our page on how long a marathon is explains where the full distance came from.

In other terms, the half marathon distance is about 69,200 feet, or 52.7 laps of a 400-meter track. It's a little over twice the length of a 10K, which is 6.2 miles. Every certified half marathon in the world covers the same 13.1 miles, whether it's flat or hilly, big or small.

Why your watch says 13.3 miles

Don't be surprised if your watch disagrees at the finish. At a German marathon and half marathon in 2016, Pobiruchin and colleagues (2017) collected distance readings from runners' own devices. On the certified half marathon course, 179 GPS sport watches averaged 21.18 kilometers, or 13.16 miles. Phones running a tracking app averaged 21.40 kilometers, or 13.30 miles, and individual readings ran from 12.4 to 14.0 miles. The authors put most of the extra distance down to runners not following the shortest racing line. Courses are measured along that shortest line, and nobody runs every corner perfectly.

How Long Does a Half Marathon Take for an Average Runner?

About two hours for men and just under two and a quarter hours for women, on average. RunRepeat's dataset of race results from 1986 to 2018 gives an average half marathon pace of 5:40 per kilometer for men and 6:22 for women. Over 21.0975 kilometers that's about 1:59:33 and 2:14:19.

A single well-run race can look faster. At the 2017 Ljubljana half marathon, 7,258 finishers ran an average of 3.14 meters per second for men and 2.77 for women, which is about 1:52 and 2:07. Big global averages pool decades of results from every kind of course and field, while one city race reflects the runners it happened to draw. Both give you a fair benchmark. A first half marathon usually takes somewhere between about 2 hours and 2 hours 45 minutes, which is a perfectly normal first result.

Half marathon pace chart

If you know your usual pace for a longer run, this chart gives your likely half marathon time:

Finish times for 13.109 miles at an even pace, rounded to the nearest second. The 9:09 row is rounded from 9:09.3, the exact pace for a 2-hour half.

Half Marathon Times by Age and Sex

Age changes half marathon times less than most people expect. In an analysis of 300,757 German marathon and half marathon runners, Leyk and colleagues (2007) found mean times were virtually identical for every age group from 20 to 49. From 50 to 69, times slowed by only 2.6 to 4.4 percent per decade. On a 2-hour half, that's roughly 3 to 5 minutes for each 10 years past 50.

The Ljubljana data show the same gentle slope. Runners under 25 were the fastest group and runners over 54 the slowest, at about 1:48 against 1:58 for men and 2:04 against 2:14 for women, by our arithmetic from the published speeds. Age also mattered less in the half than in the marathon on the same day.

The gap between men and women is bigger in the half than in the full marathon, which surprises a lot of runners. Women were 13.4 percent slower than men in the Ljubljana half and only 7.6 percent slower in the marathon. Leyk's German data showed the same pattern, with women about 13 percent slower in the half and about 10 percent slower in the marathon. A likely reason is who enters. The half draws many more newer runners, especially women, while the women who take on a full marathon tend to be a more experienced group. In Ljubljana, women in the full marathon actually ran faster on average than women in the half.

Is 2 Hours Good for a Half Marathon?

Yes. A 2-hour half marathon means averaging 9:09 per mile, or 5:41 per kilometer, for 13.1 miles. That's right at the global average for men and about 14 minutes faster than the average woman in RunRepeat's data. Breaking 2 hours is a goal a lot of half marathoners chase, and it's a good time by almost any measure.

How you pace it matters as much as your fitness. In Ljubljana, every age group of both sexes ran each section of the half a little slower than the one before, but half marathoners held a more even pace than marathoners. Only 29.8 percent of half marathoners finished with a faster final stretch, against 71.1 percent of marathoners, who also paced their races less evenly. For a sub-2 attempt, that means running the first few miles at goal pace rather than faster. These are the checkpoints to watch:

Split times at an even pace, rounded to the nearest second.

Is 2.5 hours good for a half marathon?

Yes, especially for a first half or a run-walk race. Two and a half hours means 11:27 per mile, which is slower than the averages above but well inside the range most first-timers finish in. Plenty of runners take walk breaks at every mile and still finish around 2:30. What matters for a first half is covering 13.1 miles comfortably and wanting to run another one.

Can I Run a Half Marathon If I Can Run a 10K?

Yes. If you can run a 10K comfortably, you can be ready for a half marathon in about three months of gradual training, and your 10K time already tells you roughly what to expect. In a survey of 2,303 recreational runners, Vickers and Vertosick (2016) found the classic Riegel race-time formula (1981) predicted times well for races up to the half marathon. It only fell apart at the full marathon, where it ran too optimistic. Here's what the formula predicts from a 10K, assuming you've trained for the longer distance:

Predicted with Riegel's formula, half marathon time = 10K time x (21.0975 / 10)^1.06, which multiplies your 10K time by about 2.21. Paces are our arithmetic.

If you haven't raced a 10K yet, our page on how many miles a 10K is has mean 10K times by age and sex to start from.

What changes after 10K is mostly time on your feet and fuel. A 60-minute 10K runner will be out on the course for over two hours, long enough that carbohydrate during the race starts to help. Our guide to what to eat before a long run covers the pre-race meal, and our 12-week half marathon training plan covers how fast to build the long run and how to fuel during it. The heart risk is small. In 10.9 million runners in U.S. marathons and half marathons from 2000 to 2010, Kim and colleagues (2012) recorded cardiac arrest in 0.27 per 100,000 half marathon runners, about one in 370,000, against 1.01 per 100,000 in marathons.

If I can run 7 miles, can I run a half marathon?

Yes, with some training. Seven miles is a little over half the distance, so you have the base, but jumping straight to 13.1 is a big step. Most plans add about a mile to the long run every week or two, with an easier week now and then, so from 7 miles you'd usually want six to eight weeks.

If I can run 10 miles, can I run a half marathon?

Almost certainly. Ten miles is about three quarters of a half marathon, and many training plans peak with a long run of 10 or 11 miles rather than the full distance. If you've run 10 miles comfortably in the last few weeks, rest well in the final week and the crowd and the occasion will carry you the last 3.1.

How Long Does It Take a Beginner to Walk a Half Marathon?

Walking a half marathon takes most beginners about 3 hours 45 minutes to 4 hours 20 minutes. Comfortable walking speeds for healthy adults under 60 run from about 2.9 to 3.2 mph in a meta-analysis by Bohannon and Andrews (2011), and our 5K page breaks those speeds down by age and sex. At 3 mph, 13.1 miles takes about 4 hours 22 minutes. At a brisk 3.5 mph it's about 3 hours 45 minutes, and at a fast 4 mph about 3 hours 17 minutes.

Check the time limit before you enter. Plenty of half marathons close their courses at around 3 to 4 hours, which an easy 3 mph walker won't make. Walkers who can hold a brisk 3.5 to 4 mph finish in about 3 hours 15 minutes to 3 hours 45 minutes, which fits inside a 4-hour limit.

How Many Steps and Calories Is a Half Marathon?

A half marathon is about 19,000 to 23,000 steps for a recreational runner finishing in 2 to 2.5 hours, and about 25,000 to 30,000 for a walker. Those figures are about twice the 10K counts and come from the same measured step rates our 5K page cites: about 154 to 160 steps a minute for newer runners and 114 to 129 for walkers.

A half marathon burns roughly 1,150 to 1,910 calories for a runner weighing 120 to 200 pounds. Body weight sets most of that, and pace hardly changes the cost of each mile. Lab measurements by Wilkin and colleagues (2012) put running at about three quarters of a calorie per pound per mile and walking at a little over half, and our article on how many calories a mile burns explains why.

Gross calories over 13.1 miles, rounded to the nearest 10, using the per-mile rates from that study.

What This Means for You

Keep the core numbers in your pocket: 13.1 miles, 21.1 kilometers, about 2 hours for the average man and about 2 hours 14 for the average woman, and about 4 hours for a walker. Run your 10K time through the prediction table, pick the slower end of your range for a first race, and aim to finish wanting more. A half marathon you enjoy is the one that leads to the next, and when that day comes, our page on how long a marathon is covers the step up.

Three months is long enough for life to get in the way, and the build-up is where most first half marathons are won or lost. Weeks four to eight are when the novelty wears off and the long run starts to feel like homework. That's a consistency problem, and it responds best to a routine you look forward to. As Sarah, 27, put it: "First app that made exercise feel like something I chose, not forced."

The two strength sessions in a half marathon plan are the easiest to drop, so they're worth handing to a workout app built to keep you motivated. FitCraft's 3D AI coaches lead dumbbell and bodyweight strength workouts plus yoga and mobility sessions, calendar tracking shows the weeks you've kept, and a streak gives you a reason not to skip the next one.