How Long Is A Half Marathon? 4 Ways To Measure It

So how many miles is a half marathon, seems like an easy enough question.

The official half marathon distance is 13.1094 miles or 21.0975 kilometers in length.

This is how long any standard half marathon that you enter would (or should) be.

(For a full marathon it is just double this, 26.219 miles or 42.195 kilometers.)

This oddly specific half marathon length originates from half of the full marathon distance – which itself has a strange history, shaped by 3 world events and eventually being settled for the 1908 London Olympics (more on that here).

So now you know how many miles is a half marathon, thanks for reading!

But wait!

If you want to look at a half marathon length in a more unconventional way, let’s look at how to measure a marathon comparatively, subjectively, and emotionally!

how long is a half marathon

Half Marathon Length: Objective Comparisons

We know that the half marathon is 13.1 miles long, but how about we look at some different answers to ‘how long is a half marathon?’

How Many Steps In a Half Marathon?

The average person running a half marathon will take around 20,000 steps. That is a lot of steps!

The average American will walk 4,000 steps in a day. So you would take 5x as many steps as the average person in America.

Let’s look at this distance in another way.

If you have watched any track events such as the 100m sprint, then you will be familiar with a sports track. The typical sports track is 400m long.

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So how many 400m laps would you have to do if you wanted to run a half marathon?

The answer is…

Nearly 53 laps! That is a lot of laps.

How about 1 more comparison?

How long is a half marathon compared to the Las Vegas strip?

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The Las Vegas Strip is 4.2 miles long, so if you are in Las Vegas and are itching for a stretch of your legs, then stand up from your slot machine and run up and down the strip just over 3.1 times.

And in just over 2 hours you can be back in the casino (and who knows maybe it will make you lucky).

Now let’s look at the half marathon distance more abstractly.

half marathon Length Measured By Effort

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A half marathon is 21.1 kilometres long, so roughly like running a 10k race twice, with a little bit added on the end.

A 10k race sounds easy at half marathon pace, so why is a half marathon just that bit harder?

For most people, aiming for between a 2 hour and 2 and a half-hour time in the half marathon is what we are looking to get, but for a 10k race, the average time is about 50 minutes.

50 minutes x 2 = 1.40 hours

So why do you run half marathons slower?

The answer is that it’s harder to maintain race pace the longer you run, so you have to run with a slower pace for longer runs.

how long is a half marathon

Burning Fuel On The Half Marathon

For those of you that have run a half marathon before, you all know that the first 5 miles are blissful and full of smiles, waving to family and thinking “Why do I not do this more often?”

You are in ‘game on’ mode and you feel fit and ready to do this!

Then around mile 6 something starts to happen in your body which is the beginning of a new phase in the half marathon experience.

Your effortless cruising becomes slightly more effortful and you are having to push yourself harder just to keep on your pace for your race.

This could be your legs starting to get tired, or maybe you just need an energy gel to keep yourself going.

As you keep running, your legs continue to feel heavier and you keep having to push harder and harder to keep up that pace, maybe this is the moment where you start to slow down and finishing becomes top priority.

Your energy stores are beginning to deplete, and you’re in danger of hitting the wall as your body runs out of readily-available fuel sources (ATP).

Burning fat is a lot more inefficient than burning carbs and sugar.

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This is why when you do eat an energy gel, you get a sudden burst of short-lived energy. The sugar just gets straight into your system and your body can quickly turn it into energy.

As this goes on you may experience the feeling of “hitting the wall”, that feeling of no energy and every moment in the race ahead looking like an insurmountable challenge.

For those of you who think that you are the only ones to hit the wall, check out Sian Walsh and Wendy Ingraham in this 1997 Ironman Triathlon video where these two elite athletes fought on hand and knees for fourth place in a Hawaii Ironman World Championship.

In most cases, as you see the finish line or the sign for the last kilometer you get a second wind of energy and you start to feel a little better but it can still be a tough battle to get home.

On the next graph, I have plotted glycogen levels against your level of perceived effort over time.

Screenshot 2021 11 13 at 10.45.34
As you can see, from the moment you start running your energy level is getting depleted, which is making the run seem harder and harder as you go along.

If you don’t try and stay on top of your levels soon you will feel The Wall approaching…

Half Marathon Distance, Measured By Emotions

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At the beginning of the last section, I talked about the euphoric feeling at the start of each race.

This is part of the 7 emotional stages of a half marathon:

  • The high.
  • Suppression.
  • A twinge of panic.
  • Delusion.
  • Rock Bottom.
  • The Silver Lining.
  • Change (Finish Line).

#1: The High (Miles 1-3)

The race line is full and your happily chatting away to others and doing last-minute warming up.

As you start, you have adrenaline pumping in your system, you are trained and hopeful for the race ahead and you are full of energy, smiling at the crowd as you go.

#2: Suppression (Miles 3-5)

It is still early in the race and you feel unstoppable. Many runners often decide to speed up, making the most of all this energy they have in the tank, forgetting how much running is still to come…

A bad mistake.

#3: A Twinge Of Panic (Miles 5-6)

This is that moment of something starting to feel slightly off. Your legs are slightly heavy, or is your stride off? All you know is that the race is harder than 10 minutes ago.

This moment is quickly followed by…

#4: Delusion (Miles 6-8)

Your brain keeps telling you ‘you are fine’ and it’s all in your head. So you keep pushing on and ignoring the signs of what is to come.

That niggling worry is nothing, just focus on running and it will pass.

But as you keep running, however, it becomes more and more difficult to ignore what is about to happen.

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#5: Rock Bottom (Miles 8-12)

Time can really slow down here, feeling each minute as you continue to push around the course.

If you are out of energy and have pushed too fast at the beginning then this is where you’ll encounter the wall.

The energy is gone and there is little left in the tank.

You can tell yourself an easy escape route ‘should stop and walk it out?’ who cares about my time, or maybe just slide off into the crowd and no one will notice?

These are the tough miles towards the end of the race, where you have to dig deep and just keep going, no matter how much you keep wanting to quit.

The finish line is getting closer by the step.

#6: The Silver Lining (Miles 12-13)

For most people, this comes at the 1km to go sign or seeing their watch tick over to the last mile or kilometre left of the race.

You often get a second bout of energy here and see a lot of people start running again after a kilometre or two of walking. You are almost at the finish line so are going to finish strong!

Endorphins and adrenaline get released into your system and your body starts to feel better again.

Often you will have family waiting for you as well, so have to look good for the inevitable photo shoot, when all you want is chocolate and biscuits and to lie down.

And finally,

#7: Change (Finish Line)

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As you cross the finish line a wave of emotions rush over you and you are overjoyed to have completed the race.

It is a great accomplishment, and you should be proud.

In the following days after you have recovered, people often forget the discomfort and just remember the good times.

Soon you will be scrolling through race sign up websites and looking for the next challenge, another half, or maybe a full marathon?

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If this sounds like you and you think you might be interested in trying a full marathon, then check out this guide on how to train for your first marathon and a training guide for you to follow.

And if half marathons are more your style but you want to get better and avoid that wall and push towards better times, then check out the free training plans here on our website.

Tom McMeekin-Donnelly

Tom McMeekin-Donnelly

Tom McMeekin-Donnelly is a runner, outdoor enthusiast and cyclist. Tom competes in ultra-marathons in the UK and Ireland. Tom runs anything from a marathon to 100 miles. He can often be found in the mountains around his home in Ireland.

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