Race time predictor
Enter one recent race, and we'll predict your finishing time at other distances using the Riegel formula.
Pace unit
Target distances
Your known race result
| Distance | Predicted | Actual | Pace (min/km) |
|---|---|---|---|
| 1K | 4:00 | — | 4:00 |
| 1 mi | 6:37 | — | 4:07 |
| 3K | 12:48 | — | 4:16 |
| 5K | 22:00 | 22:00 | 4:24 |
| 10K | 45:52 | — | 4:35 |
| 15K | 1:10:30 | — | 4:42 |
| 10 mi | 1:15:57 | — | 4:43 |
| Half marathon | 1:41:12 | — | 4:48 |
| 30K | 2:26:59 | — | 4:54 |
| Marathon | 3:31:00 | — | 5:00 |
| 50K | 4:12:36 | — | 5:03 |
Predictions use the Riegel formula with exponent 1.06. Accuracy drops as the gap between your known race and the target grows — be skeptical when predicting marathon time from a 5K.