How to estimate your marathon time?

Are you about to embark on a marathon training and want to make a good estimate of your target time? With Campus, we explain the important elements to consider to estimate your time on race day. 

Whether you are a new marathon runner or experienced, completing a marathon is an achievement, no matter how long it takes you to finish it! In a marathon, time profiles vary a lot. But if you enjoy the challenge, or if you already have a time on this distance, it might be interesting to consider a time goal to push your limits. Thus, you could achieve a new performance on the big day that matches your training. 

To help you calculate your time estimate for the marathon, you can start by basing yourself on the average of other runners. This way, you can have an idea of how to position yourself to begin your training.

In our articles on average running speed of men and women across different distances, we already discussed the average times achieved during marathons.

In summary, among the 38,620 women running with Campus, their average marathon time is 5 hours and 47 minutes, which corresponds to an average speed of 7.3 kilometers per hour and thus a pace of 8 minutes and 10 seconds per kilometer.

And regarding men, among 75,000 running with Campus, the average for a marathon is 4 hours and 16 minutes. This corresponds to an average speed of 9.9 kilometers per hour, and therefore a pace of 6 minutes and 07 seconds per kilometer. 

The answer to this question primarily depends on your experience with the distance.

If you are going to run your first marathon and want to calculate your time estimate for this distance, we especially advise you to take a step back and listen to yourself. The estimate is a good way to stay motivated during your preparation, to know where you are going, and especially to start at the right paces on the big day and not let yourself be carried away by the atmosphere.

It is better to avoid putting pressure on achieving a specific time: you do not yet know how your body and mental strength will react over a long distance like this. Do not try to complete your race based on a minute-by-minute estimate.

If you have already run a half-marathon, you can base yourself on the time you took by decreasing your average speed by about 1 km/h (since you will need to maintain the pace for a longer time). You can also multiply your time on a half-marathon by a value between 2.1 and 2.4 and take into account your experience, your plan, and your endurance qualities. These extrapolation methods for a marathon remain relative for the first marathon.

The best option is to have a personalized training plan to prepare for this long-distance event. As you progress through the plan, you will be able to grasp the right pace for your first 42 km. 

If you have already run one or more marathons, you surely have a strategy for your race management, your target heart rate zone on the big day, and you have visualized the expected sensations. It will be easier for you, and surely more relevant, to estimate the time you will take next time thanks to pace workouts during your training. This will allow you to compare the data from your workouts to the data from your previous marathons.

To help you set your time goals, you can use our pace calculator. It is free and very easy to use. It will give you a time estimate: you can visualize your potential progress.

In running, it's better to talk about average pace rather than speed, indeed speed does not allow the same granularity in the analysis of a run and its estimation.

With these formulas, you can estimate the time it will take you over the marathon distance. You can also keep it simple and use our pace calculator or start a Campus plan in 12 weeks. 

As we have just seen, it's best to think in terms of pace. Using the previously explained formulas, to run a marathon in 4 hours, you will need to run at a pace of 5 minutes 40 seconds per kilometer, which is a speed of 10.6 km/h.

This data will allow you to set milestones by determining your split times throughout the 42 kilometers. Knowing your split times gives you better race management. This will allow you to better understand the overall flow of the race.

If you are more experienced, perhaps you have a goal around 3 h 15 for the marathon. To do so, you will need to run at an average speed of 12.95 km/h, which is a pace of 4 minutes 37 seconds per kilometer.

The more you try to lower your time, the more your race management will become important and this time estimate for your marathon must be as accurate as possible.  

A good method to see if your estimate is accurate is to perform workout tests, as if you were running a marathon. You can do them during your long runs, these endurance moments where conditions are most optimal to test your paces and your gear. 

In the end, estimating your marathon finish time is not just about plugging numbers into a calculator—it’s about connecting your training, your long run sessions and your race performance in shorter events to what’s possible on the big day. Whether you’ve used a running pace calculator, based your start on previous finish times or simply targeted a goal for your 5k race as a stepping stone, what matters is the translation of those race times into a realistic marathon pace. Use your long run workouts to validate your target pace, apply your race times to refine your prediction, and trust your preparation. By doing so, you’ll arrive at a finish-time estimate that reflects both your endurance and your ambition—meaning you’re not just running the marathon, you’re executing it with intention.
You now know how to estimate your time over a marathon. This will primarily allow you to set goals or ideas for pacing times at different stages of the race. These milestone points will assist you in managing the race. Remember that as you cross finish lines, you will be able to better and better estimate possible performances.