“I’m running my first half marathon. How can I estimate my half marathon time?”
Finishing times for most half marathons (13.1 miles) range from a little over an hour for elite runners to 3+ hours for slower runners or walkers.
Although the goal for first-time half marathoners should be to finish the race (an amazing accomplishment!), it can be helpful to have a general idea of how long it will take you to run the race so you know how to properly pace yourself. You’ll also be able to tell your supportive spectators approximately when they should look for you.
Predicting race times is never an exact science, but you can use a chart or calculator to determine a ballpark half marathon time, based on a recent race. Here is a useful calculator to try:
Chicago Endurance Sports Race Time Predictor: Just plug in the distance and your time from a recent race. The calculator then shows you how you might perform in your target race.
How Accurate Are Half Marathon Time Predictions?
Keep in mind that your half marathon time prediction is just an estimate of what you might achieve, if you do the appropriate training for the half marathon distance. It doesn’t mean that you’ll automatically run that time because of your fitness level. In addition, the course terrain, weather conditions, and how you’re feeling that day will also factor into your race time.
In most cases, only experienced half marathoners will achieve their predicted time. If you’re a beginner runner and it’s your first half marathon, focus on completing the race and celebrating your achievement. If you’re looking for a ballpark finishing time prediction for your first half marathon, add 5 to 10 minutes to the calculator prediction.
How to Get a More Accurate Race Time Prediction
If you can input a similar race distance (close to your target race) when using a table or calculator, you’re likely to get a better result. So, for example, you’re more likely to get an accurate prediction for a half marathon time based on a 10K race time, rather than a mile race.
It’s also good to use a time from a recent race, ideally no more than six weeks before your race. If it’s more time than that, your fitness level may have changed (for better or worse) and the times won’t be as accurate.
Also, if you’re running local races, running a race within a few weeks before your target race increases your chances of having similar weather conditions for both races, which will also make your time prediction more realistic. An added bonus is that you get to test out your race outfit and make sure it’s suitable for the weather.
What to Do With Your Race Time Prediction
Once you have a reasonable estimate for your half marathon time, you can use a race pace calculator to determine what your average pace should be for the race. Many half marathoners like to use a race pace estimate to set a race plan, which can help ease some anxiety about the race.
You’ll want to start your half marathon at least 5 to 10 seconds slower than that estimated pace, to make sure you don’t make the common racing mistake of starting out too fast. If that pace feels too fast, slow it down even more and continue to be conservative until you get to mile 7.
Once you’ve reached mile 7, if you’re feeling comfortable, you can slightly lower the pace by 5 seconds. Hold steady at that pace until mile 10. With just 3 miles to go, you can run based on how you’re feeling. If you have some energy left in the tank, it’s safe to slightly pick up the pace and finish strong.
More About Half Marathon Times
If you’re curious where you might place (top 10%, middle of pack, etc.) in a particular half marathon, look at the results from last year’s race. The size of the field and the range of times will probably be fairly similar this year.
Some half marathons do have time limits, such as three hours. So if you’re a slower runner or walker, make sure you find out if a half marathon you’re interested in has a cut-off time. There are plenty of half marathons that are walker-friendly, so you don’t worry about finding one that’s right for your fitness level.
Running coach, avid runner, and fitness writer Christine Luff is an RRCA-certified running coach and ACE-certified personal trainer. Founder of the website Run for Good and author of the book Run for Good: How to Create a Lifelong Running Habit, she coaches runners, from beginners to advanced, who are training for races, from 5Ks to marathons.
