Race Time Predictor (Riegel)
Predict a race time at one distance from a result at another.
From one distance to another
If you know your time over one distance, you can estimate what you might run over another, since running performances across distances are related. This predicts a race time at a target distance from a known result, useful for setting goals and planning pacing.
Enter a known time and distance and a target distance to see a prediction.
A useful estimate with real caveats
Race prediction uses the established mathematical relationship between times at different distances, and it works reasonably well between comparable distances. But it assumes suitable training for the target distance, which is a big assumption — predicting a marathon from a 5k result will flatter you if you have not built the endurance a marathon demands, since longer races depend heavily on specific endurance training the formula cannot know about. Individual strengths, whether you lean toward speed or endurance, also shift the reality. Treat a prediction as a goal-setting guide and a pacing starting point, not a guarantee, most reliable when the two distances and your training are well matched.
Race Time Predictor (Riegel) FAQ
How does race prediction work?
It uses the established relationship between times at different distances to estimate one from another — most reliable between comparable distances.
Why might a long-race prediction be optimistic?
Because it assumes you have trained for that distance. Predicting a marathon from a 5k flatters you without the specific endurance a marathon demands.
Is my data uploaded?
No. The calculation happens in your browser.