Race Time Predictor
Predict your finish time for any race distance based on a recent result. Uses Riegel and Cameron formulas.
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Predicted Times
Riegel Prediction
3:35:48
Pace: 5:07/km
Cameron Prediction
19:27
Conservative
3:55:01
Fatigue factor: 1.10
Aggressive
3:26:47
Fatigue factor: 1.04
All Distance Predictions
| Distance | Predicted Time | Pace (min/km) |
|---|---|---|
| 1 Mile | 6:46 | 4:12 |
| 5K | 22:30 | 4:30 |
| 10K | 46:55 | 4:41 |
| 15K | 1:12:06 | 4:48 |
| 10 Mile | 1:17:41 | 4:50 |
| Half Marathon | 1:43:30 | 4:54 |
| Marathon | 3:35:48 | 5:07 |
| 50K Ultra | 4:18:20 | 5:10 |
How Race Prediction Works
The Riegel formula (T2 = T1 × (D2/D1)^1.06) is the most widely used race prediction model. It accounts for the fact that you slow down proportionally as distance increases. The fatigue factor (exponent) can be adjusted: beginners typically slow more at longer distances.
The Cameron formula is an alternative that some runners find more accurate for very long distances. We show both so you can compare. Your actual result will depend on training, nutrition, weather, and race-day execution.
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