Here at LFTO, we've published advice and plans for basically every race length. From our guide to how to run your first 5k all the way up to our 12-week ultra marathon training plan, we've covered the long and short of distance runs. And we've noticed that one particular race length is by far our most searched and read: the humble half marathon.
A half marathon is the perfect race length for runners at basically every level (except super duper beginners, but even they might get away with one if they're already fit and possess some grit). This is because it's a manageable distance which can be quite easily achieved with for first timers after some training, but your finish time can also always be improved.
Athletes at every level still like to enter the occasional half marathon and try to beat their PBs. These races also make excellent training venues for managing your pace and energy levels over long distances. If you've never done one, we'd highly recommend it.
How long is a half marathon?
A half marathon is officially 21.0975 kilometres, or 13.1 miles. However, don’t be surprised if your GPS watch shows a slightly longer distance by the time you cross the finish line. This happens because races are measured along the shortest possible route—the exact line taken by the measuring equipment, which often follows the tightest corners.
In some races, like the London Marathon, this “racing line” is even marked with a blue line painted on the ground. But sticking precisely to this path is nearly impossible due to other runners, water stations, and natural weaving during the race, meaning you'll likely cover a little extra distance.
What’s the average finish time for a half marathon?
Since half marathons are so popular with different skill levels and age groups, the answer to what makes a good half marathon time is also highly varied. Let's break down the data to get a better understanding of who should be aiming for what time:
What is a 'good' half marathon time?
Well, if we check the tippity top end of 'good', we'll find that the fastest half marathon time to date is 57 minutes and 30 seconds. It was set by Yomif Kejelcha, an Ethiopian distance racer who smashed the rainy Valencia half in October 2024. He ran at an average pace of about 2 minutes and 40 seconds per km. Or 4 minutes and 18 seconds per mile.
That pace is almost exactly twice as fast as my average running pace, according to my Strava which WILL REMAIN ANONYMOUS! Sufficed to say, any sub 1-hour time is superhuman, and any time under an hour and a half is hugely impressive.
"A good time is very subjective." Comments our team's expert ultra runner and professional coach, Lily Canter. "It really depends on what your goal is. Is it to enjoy the experience and finish the race or to smash out a PB? It’s good to go into a half marathon knowing which goal you are aiming for.
"The best data I’ve seen is from Running Level which records the average male time as 1hr 43min 33sec and the average female time as 2hr 12sec. But this will vary hugely depending on your age, sex, training and level of experience."
We've been rummaging around the race results for last year's London Landmark half marathon. It's a great race to pull data from because it has several thousand participants across a wide range of ages and skill levels. Ideal for calculating mean averages - which we have done, but we'll get to those. For now, here's a break down of the fastest male and female runners at this race in each age category:
Best women's London Landmark half marathon times by age
17-19: Tabitha Woodhouse - 1:23:14
20-29: Leah Bright - 1:25:05
30-39: Lisa Nottingham - 1:24:51
40-49: Samantha Harrison - 1:35:02
50-59: Pamela Johnstone - 1:42:23
60-69: Harriet Gardner - 1:50:34
70+: Margaret Fisher - 2:15:10
Best men's London Landmark half marathon times by age
17-19: Harry Ward - 1:15:12
20-29: Thomas Hobbs - 1:07:13
30-39: Ben Johnson - 1:07:55
40-49: Chris Taylor - 1:12:22
50-59: Steve James - 1:18:12
60-69: Graham Wilkins - 1:26:10
70+: Robert Jones - 1:44:55
How to finish in the top 10% for your age group
Of course, for most of us, aiming squarely at a first place finish is a bit pie in the sky. A more attainable (but still fairly lofty) goal is finishing within the upper tenth percentile.
Times to finish in the top 10% of men
17-19 | 01:38:07
20-29 | 01:37:25
30-39 | 01:37:13
40-49 | 01:40:45
50-59 | 01:45:29
60-69 | 01:55:00
70+ | 02:11:40
Times to finish in the top 10% of women
17-19 | 01:50:40
20-29 | 01:48:15
30-39 | 01:49:50
40-49 | 01:54:18
50-59 | 02:02:25
60-69 | 02:15:00
70+ | 02:31:42
Overall, to land yourself in the top 10% of all participants, you'll need to finish inside 01:46:27. Since 18,959 people participated in the London Landmarks half marathon, you'd be aiming to be one of the first 1,896 finishers.
How to finish in the top half
It's important to remember that simply finishing a half marathon is no easy feat. It's a huge accomplishment – something to be proud of regardless of your pace. That said, if you're looking to approach your first half with a competitive mindset, why not aim to finish in the upper 50th percentile?
Times to finish in the top 50% of men
17-19 | 02:00:31
20-29 | 02:11:04
30-39 | 02:00:00
40-49 | 02:08:33
50-59 | 02:14:44
60-69 | 02:25:30
70+ | 02:45:55
Times to finish in the top 50% of women
17-19 | 02:18:20
20-29 | 02:27:40
30-39 | 02:21:18
40-49 | 02:28:40
50-59 | 02:40:10
60-69 | 02:58:30
70+ | 03:15:01
Again, finishers of the London Landmarks half had to clock in under 02:15:05 to hit the top 50%. It's interesting to note that the mean average finish time for this race was a bit over the median. At 2:18:58, the mean average finish time reminds us that, while the racers at the front are battling it out over millisecond advantages, the majority of participants are relaxing and going their own pace.
Finishing times stretched as far as 10+ hours at this particular race – since there's always the admirable few who go ahead and stroll the whole thing!
How can you estimate your half marathon running time?
Lily Canter argues that the best method for estimating your time is “to do a 5k time trial and then use the VDOT calculator to see your predicted half marathon time. This will be a good time for you as an individual, rather than simply relying on age/sex based data. I find the forecast to be pretty spot on as long as you put in the training.”
Trail vs road: expanding your half marathon horizons
If you’ve already tackled a road half marathon, or you’re simply looking for a fresh challenge, why not consider a trail half marathon? While road races typically take place on smooth, predictable surfaces, trail half marathons invite you to trade tarmac for scenic routes through forests, hills, and mountains. The terrain is varied and often more technical, with uneven paths, rocks, and even streams to navigate, making it as much about agility as speed. You'll need a good pair of trail running shoes, of course.
Trail half marathons also tend to focus less on chasing a specific time and more on enjoying the experience and the natural surroundings. The elevation changes mean you’ll likely face steep climbs and descents, which can slow your pace but add an extra layer of accomplishment to the challenge. And while road races are often packed with spectators cheering you on, trail events tend to offer quieter, more intimate vibes - with the occasional cow or sheep as your audience.
Switching from road to trail doesn’t mean abandoning your road running skills, but it does require some adjustments. Stronger ankles, grippier shoes, and a willingness to embrace a bit of mud are all part of the package. Whether you’re craving new scenery, a break from the stopwatch, or a chance to push your limits in nature, trail half marathons offer a rewarding alternative to road racing. No guesses for where our bias lies.