How to Predict Your Marathon Time

Predicting your marathon finish time is useful for setting pacing strategy, training targets and race expectations. One of the most common mistakes runners make is setting a marathon goal time that is not based on current fitness.

A common way to estimate marathon performance is to use a recent race result, such as a 5 km, 10 km or half marathon, and apply an endurance prediction formula. These formulas assume that performance declines at a predictable rate as distance increases.

The most commonly used prediction method is based on the Riegel formula, which estimates performance over longer distances from shorter race results. While it is not perfect, it provides a useful starting point for pacing and goal setting.

For example, if you run a half marathon in 1 hour 40 minutes, you can use a prediction formula to estimate your likely marathon time. This helps you avoid starting the marathon at a pace that is too ambitious and unsustainable.

You can use the Marathon Time Predictor on this site to estimate your marathon finish time from a recent race or hard training effort.

It is important to remember that marathon performance is influenced by more than just speed. Long run endurance, fuelling strategy, pacing, weather conditions and course profile all play a role. A prediction tool provides a starting point, but training and race execution determine the final result.