All runners and athletes who desire to improve their race performance can benefit from Race Predictor. Our running time calculator will predict the time for another run competition based on your prior running results. Check whether you can travel extra distance in a reasonable amount of time and at a comfortable pace without doing any sophisticated analysis. A short instruction on how to use the calculator, a discussion of certain aspects of training, and a few race day preparation advice may all be found in the article below.

While you are here, you should also read more about the Bruce Protocol METs test, to make evaluation of cardiovascular fitness, aerobic endurance and diagnose cardiac problems. Related to this subject, our tools can help you with your calculations, such as Distance or Manhattan Distance Calculator, but also this Marathon Pace Calculator, to calculate your pace. As for testing, there is also our Cycling Heart Rate Zone tool.

Take a look other related calculators, such as:

Running time – how to predict?

Our running time calculator is based on a mathematical formula published in Runner’s World Magazine in 1977. Peter Riegel, an American research engineer and marathon runner invented the equation. The statement can be used to forecast race timings for runners and other athletes who have previously demonstrated a specific level of performance at a different distance. The sports world has generally accepted the method throughout the years, owing to its high computation accuracy and ease of use.

Riegel’s formula:

T_2 = T_1x(\frac{D_2}{D_1})×1.06


  1. T₁ is the time achieved recently on distance D₁
  2. T₂ is the predicted time for distance D₂
  3. D₁ is the distance over which T₁ time was achieved
  4. D₂ is the distance for which T₂ time is foreseen

Pete Riegel’s formula assumptions

There are a few things not to forget about Riegel’s equation before using the running time predictor:

  1. It is assumed that a runner has completed the necessary training for the distance they decide to run. A strong performance on the 10km course the day before does not imply that you can run a half-marathon in 1h 30 minutes today.
  2. Assumes that an athlete does not have a solid inherent aptitude for speed or endurance. Some people will always do better than others regardless of how much they train.
  3. The computations are less precise for times less than 3.5 minutes and more than 4 hours.

The advantage of this approach is that it is distance-adjusted; it does not just double, for example, a 6 km forecast for a 12 km estimate.

How does the race time calculator work?

Let’s go over the following example together to make sure you’re utilizing the running time calculator correctly:

Fill in the following distance from the most recent race result: Assume it was a half marathon, with D1 equaling 22 kilometers.

Fill in the following information about the time you took to cover that distance: T1 was 1h 57min 26s, which isn’t terrible!

Choose a new running distance: I prefer lengthy runs! D2 equals 30 kilometers.

T2 = 2h 43min 8s is the latest distance prediction – that’s a lot of sweating!

How should I prepare for race day?

Many factors can affect the preparation of our condition and form. It’s not as easy as we think. Some of the elements of our preparation are:

  1. type of training,
  2. training intensity,
  3. nutrition,
  4. biological recovery,
  5. health condition.

You must not forget that not every race is the same, and not every race requires the same preparation. Some of the types of races are mountain, marathon, sprint, brisk walking, and the like. Each of these races has its own speed, rhythm, unique distribution of power, calorie intake needed to run the race itself, and the like.

Predicted Race Performance table

4 km23:419:32
5 km30:009:39
8 km49:229:56
10 km1:02:3310:04
12 km1:15:5310:11
15 km1:36:0810:19
HALF MARATHON2:18:0010:32

Race day preparation

When the day of the race comes, more or less, the job is done. However, you certainly have some other little things that can make a big difference in your performance. Some of these things are:

  1. Rest – no matter how important training is, just as much rest is needed. Here we do not mean that you just lie down and sleep, but an active vacation, whether it is a walk at night, massages, or hanging out with friends, you decide;
  2. Warming up – warming up is inevitable before any workout. This also applies to the race itself. Warming up can save you from many injuries and pains during and after the race;
  3. Diet- Believe it or not, about 70% of a healthy body is diet and not training. A great influence of diet, food intake in our body has on the very appearance of our body but also on our performs;
  4. Mental stability – the stronger you are physical, the more you need to be mentally strong. Mental stability is 90% victory.