How Long is a Half Marathon? 13.1 Miles of Success Requires Planning

Updated: November 9, 2023

November 9, 2023 in Training guides

A Half Marathon is one of the big bucket list achievement goals for many runners and fitness enthusiasts, but how long is a half marathon? The best answer is 31.1 miles or 21km, but how long it takes needs more analysis.

In this article, we will look at how long is a half marathon for different ability groups. As a winner of 6 half marathon races and someone who has competed for over 20 years, I will share how long is a half marathon for all kinds of abilities.

What is a half marathon?

A half marathon is half the distance of the full marathon, but due to organization, training time, course length, and budget, the half marathon distance is more commonly raced.

The half marathon is 13.1 Miles long or 21 kilometers.

A half marathon can be on roads, trails, or hilly or flat terrain. Be sure to read on whether you are running a half marathon for the first time and consider yourself a beginner runner, or if you have some experience, and believe you are in the intermediate or advanced runners category.

Reasons you need to know how long a half marathon is

Reason 1 - You can train for it effectively

Understanding not only the distance but also how long in time the half marathon will likely take you gives you the best chance of success. It's important to complete some half-marathon training to enjoy the event and have the best chance of avoiding injury.

Reason 2 - You know what you are taking on

So you can tell if you are ready for it or if you perhaps would be better off at a different distance, have a look at some half marathon training plans and see if you think you have the time in your week to be able to reach the weekly mileage for example.

Reason 3 - So you can set a goal.

You may want to book in and compete in a particular half-marathon event. This could be to achieve a time, to take in the scenery, or even to visit a new country and compete in a race.

Reason 4 - So you can mentally prepare

Your whole training plan and schedule should not be solely on the physical training element. You may be an experienced runner or be looking for more than just reaching the finish line. Mental preparation is vital to allow you to do your best.

Reason 5 - Avoid injuries

How long is a half marathon

Preparing for a half marathon involves various factors and is far more than how many miles you can run. For a balanced program, you will also want to incorporate some strength training elements and drills that improve your running form.

Reason 6  - Get the correct kit

It's essential to have suitable kit. You do not have to have the very best of the market, but you do need to have kit that will allow you to prepare and race the distance safely and avoid injury; this can mean having reflective clothing if you are training over the winter months for a race in the spring.

Reason 7 - Enjoy

It's essential to realize how long the half marathon is in both distance and times so you can enjoy it on the day. You want to understand the feeling of being out on your feet running for 2 hours, for example, so that it is not a huge shock on race day.

How to understand how long is a half marathon for YOU!

How long is a half marathon

Beginner runners

For a beginner, it is an achievement to complete the distance. If it is 2 hours 30, for example, you still have completed the distance. It does make sense to know what pace to start the race at though. So do try and calculate this either by entering a 10k race or completing a 10k effort in training so you can base your running pace on it.

You may be in this category, if you have limited running experience or perhaps have not raced before and are looking for some confidence, here are our top tips to consider

1.No set time goal

You may not want to set a time to aim for, particularly as a beginner. If it is your first half marathon, you may aim for running 10 miles out of the 11 and walking some parts, or you may want to stay with a training partner.

2. Enjoy the process/Find a Routine

In training, think of covering the distance above anything else. You now know that you need to cover 13.1 miles in training. You may wish to have one longer run each ten days or so in which you gradually increase the distance.

Get used to running regularly during your week, you are building the foundations for the future and consistency in running is key.

3. Finish Strongly 

If you can reach the finish line having enjoyed the race, then it's a huge plus for preparing for your next attempt or challenge.

How long is a half marathon

Intermediate runners

How long will the half marathon take? You may expect to run around the 1.30 to 2.15 mark, or you may be looking to improve on the last time you ran.

Are you an intermediate runner?

You may have Run a 10k? Run a half marathon before? You may have some experience racing and have a time goal in mind; you could have run a 5k or 10k or maybe are looking to improve your best time for the half marathon.

3 Tips to think of as an intermediate half marathon runner

1. Focus on pacing

The pace you set off, it's crucial to have an overall goal in mind so that you can begin to learn how to pace yourself. If you run slower at the start and gradually increase your pace based on your fitness level, you are far more likely to succeed than if you start too fast. This is why running goals are so important.

2. The equipment 

It is not just the running shoes. It may also be having a running coach. If you are of intermediate level, you don't need to rush out and buy the best of everything, but having a few essential items can make a difference, particularly when thinking about recovery.

3. Your training 

If you are an intermediate runner, you will incorporate several runs in your training plan, from speed sessions to long runs, improving your endurance as your body adapts to the training.

How long is a half marathon

Advanced runners

If you are in this category, you might be running some faster times such as under 1 hour 30 and further, or you may be in one of the master age categories and finish high up in the category. My best time is 1hr 09, so if you would like to know how I got there, read on.

Three tips to think of to run as an experienced runner or advanced half marathon runner

1.The equipment, both for training and racing

If you are in the advanced runner bracket and are looking to progress further, the equipment is certainly key. You may want to invest in a pair of "super shoes" for racing. These are hugely common now and often include a carbon plate. In addition to the super shoes, you should invest in a good watch for monitoring your workouts, particularly if you do not have one yet.

2. Key workouts to run your fastest time 

Some of the key workouts for an advanced runner include:
Fast-finishing long runs
Pushing the last miles or kilometers of a long run is great when preparing for a half marathon personal record or if you are looking to compete for a placing in your age group or to place highly overall in the race.

Fartlek mixed-paced runs

These are great for a half marathon, but you do need to be in good shape to complete them. It might be something like 20 x 1 min or 1 min off, but the off needs to still be running at a relatively good pace, so you may want to aim 10 seconds per mile on the fast reps faster than your goal pace and only be 10 seconds slower per mile on the off rep so your average time is near your goal pace for the half marathon.

The key aim of this session is to respond to different surges during the race so you can go slightly above your goal pace and recover well during the race.

3. Tactics to compete and win a half marathon

Some tactics for racing and competing for the win. When racing longer races, it is important to think tactically.

Draft in a group

You may have seen cyclists use this tactic, but it can be highly useful in running as well. Rather than running on your own, having a group can not only help shield you against the weather but it can allow you to mentally switch off if the group you are with is aiming for a similar time.

Run the shortest route

You may have seen some of the major marathons have a line in the road. This is so that the runners can run the accurate distance as in a wide road race with plenty of turns and bends. If you are not running the direct route, you can end up running a fair bit further. Learn to run tangents when it's safe in training.

Race to your strengths

If you are constantly doing well in your speed workouts and have a fast sprinting pace, then tactically, it may be better for you to wait until the final KM to make your effort to win a race.

If, however, you excel in the tempo runs and long runs and enjoy running at the front you may want to do this come race day. 

Key Considerations For Successfully determining how long is a half marathon

The half marathon is a set distance to be accurate of 13.1 miles or 21 Kilometers.

However, thinking about how long it will take you depends on several factors, some of which are entirely out of your control, including:

The weather

The weather is a considerable factor when attempting to run a half marathon. If you are hoping to run your fastest half marathon time, try and pick a time of year when you will likely get optimal race conditions on race day. The wind is one of the most detrimental factors for running a fast time, as is the temperature, particularly in very hot conditions; it is far harder to run fast.

The course

If you are looking to run a fast time, running your half marathon on a flat road course is the best way to do so. Many half marathons would have a course profile available. It can sometimes be beneficial to have run a few undulations; however, a flat course with few turns generally leads to where most people get their personal best times.

Your training

Training can mean not just for this race but the training you have done in the months and years prior. Running training and success in the sport is generally built up over a number of training blocks and races.

Your experience at the distance

If this is your first time training for a half marathon, then you are likely to learn a huge amount about the distance in your first attempt. This experience can grow over time as you learn what has worked well for you, particularly in your training, for example.

Your Kit

You may think super shoes are only for the elite or advanced runners; however, they have been proven to help many runners achieve their goals. They are not only valuable for the race but can also protect your legs in training. Remember, your kit is not limited to what you will use on race day. It can also mean what you use to recover. Check out our top tips for recovery.

Alternatives to how long is a half marathon

There are many other distances and races if you think that a half marathon is too long for you in distance or time. It may just be that it is too long for you right now, and in the future, after racing some 10ks, you will be ready.

Or you could run even longer and take on the challenge of a full marathon. For example, the half marathon is, of course, exactly half the distance of the full marathon.

Remember, with good training and preparation, you can succeed and achieve your goals. There are also targets to aim for in your age group. The various age categories are often awarded prizes and trophies at major competitions.

Wrapping up

When considering the answer to how long is a half marathon. We think its more than just the distance of 13.1 miles and how long it takes by looking at average figures.

It's vital to consider the age group you are racing in as well as the course, the weather, your experience, and training.

In addition to this, knowing the average half marathon time. It might be useful initially, but with so many other factors, the best course of action is to set your own goal and aim for that, and once you have achieved that goal, work on something else. It's how I have reached a time of 1 hour and 9 minutes and how I plan to move forward.

Good luck with the training and preparation for your half marathon.

About the author 


James is an elite distance runner and has also raced triathlon for a number of years. He has a certification in swimming coaching, and a passion to help all athletes succeed in finding a balance within sport and life.