Race Time Predictor
Enter one recent race result and see your predicted finish time across every standard distance.
| Distance | Predicted time | Predicted pace |
|---|
Predictions use the Riegel formula (T2 = T1 × (D2/D1)1.06). It's a strong estimate for well-trained runners racing similar distances, but doesn't account for course, weather, or race-specific training.
How race prediction works
The Riegel formula assumes your endurance degrades at a predictable, exponential rate as distance increases. Give it one honest, recent result and it estimates what you could run at any other distance today — useful for picking a realistic goal time before you commit to a training block.
When it's less reliable
Predictions get shakier the further apart the distances are — a 5K result is a rough guide to marathon potential, not a promise. It also assumes you'll train specifically for the target distance; a great 10K time doesn't predict a marathon you haven't trained the endurance for.
Related tools
A coach can turn this number into a training block that actually gets you there.