Sports & Fitness calculator
Race Time Predictor Planning Tool
Predict race time for another distance from a recent race result using the Riegel formula.
FormulaPredicted time = current time x (target distance / current distance)^1.06
Formula
Riegel race prediction
Race predictions assume similar training, terrain, weather, and effort.
Predicted time = current time x (target distance / current distance)^1.06
A 25 minute 5K predicts roughly 52 minutes for 10K.
FAQ6 common questions for this calculator.
FAQs
Why is the exponent above 1?+
Longer races are usually run at a slightly slower pace than shorter races.
Does this work for all distances?+
It is a planning estimate and works best for reasonably related running distances.
How does the Race Time Predictor calculate the result?+
For the Race Time Predictor, it uses the Riegel race prediction: Predicted time = current time x (target distance / current distance)^1.06. A 25 minute 5K predicts roughly 52 minutes for 10K.
What information do I need to use the Race Time Predictor?+
For the Race Time Predictor, enter a recent race result. Keep the units consistent with the calculator fields and compare your setup with the worked example on the page.
How accurate is the Race Time Predictor?+
Race Time Predictor is a planning estimate based on a recent race result. It uses the Riegel race prediction, but terrain, device accuracy, fitness level, and intensity changes can move the real number.
What should I check before using the Race Time Predictor result?+
For the Race Time Predictor, check a recent race result. Fitness and calorie estimates are most useful when terrain, device, and effort level are comparable.
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Sports & Fitness guide
How to use the Race Time Predictor
Predict race time for another distance from a recent race result using the Riegel formula. The page also explains the riegel race prediction and shows a practical example: A 25 minute 5K predicts roughly 52 minutes for 10K.
- 1
Enter your details
Enter a recent race result using the Riegel formula, then complete any other fields shown in the calculator.
- 2
Check the calculation
Review the result alongside the riegel race prediction: Predicted time = current time x (target distance / current distance)^1.06.
- 3
Compare scenarios
Change one or more inputs to see how they affect the race Time Predictor result before you use the estimate.