Clinical Accuracy Verified
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Marathon Race Predictor
Predict your marathon time based on a recent race result (5K, 10K, Half) using the Riegel formula.
::
| Distance | Predicted Time | Avg Pace /km |
|---|---|---|
| 5K | 25m 0s | 5:00 |
| 10K | 52m 7s | 5:13 |
| Half Marathon | 1h 55m 0s | 5:27 |
| Marathon | 3h 59m 47s | 5:41 |
| 50K Ultra | 4h 47m 2s | 5:44 |
*Based on Riegel's Formula (Exponent 1.06). Accuracy decreases as distance increases significantly beyond your input.
The Riegel Formula
Peter Riegel's formula is the standard for race prediction: T2 = T1 * (D2 / D1) ^ 1.06Accuracy
Predictions assume you are equally well-trained for both distances.Explore More Tools
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Calculate your finish times for popular race distances (5K, 10K, Marathon) based on your pace.
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Heart Rate Zone Calculator
Calculate your 5 training zones based on Max Heart Rate or Heart Rate Reserve (Karvonen).
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VO2 Max Estimator
Estimate your cardiovascular fitness (VO2 Max) using the Cooper Test (12-minute run).