Race Time Predictor
Predict your finish times for different race distances based on a recent performance.
Choose a recent race that reflects your current fitness.
Compare the predicted times to find a goal at your next race distance. For a marathon or ultra, review the prediction alongside your long runs and fueling practice.
Look at your target race's hills, surface, and expected weather when planning your pace. Revisit your goal as you complete more training and races.
See the formula and example timesRace-time reference
| 5K result | 10K | Half marathon | Marathon |
|---|---|---|---|
| 20:00 | 41:42 | 1:32:00 | 3:11:49 |
| 25:00 | 52:07 | 1:55:00 | 3:59:47 |
| 30:00 | 1:02:33 | 2:18:00 | 4:47:44 |
How we calculate this
Target time = known time × (target distance ÷ known distance)^1.06.
The predictor and comparison tool use the same equation. The comparison reports how much faster or slower your second result is than the prediction from your first result. Differences within 1% are labeled roughly equivalent; that cutoff is a RaceThere display convention.
Sources: Vickers & Vertosick (2016): race prediction in recreational runners.
Using your results
Start with a recent race that reflects your current fitness. Predictions are most useful between similar distances; for marathons and ultras, weigh the result alongside your long runs, fueling practice, and course conditions. When comparing two results, consider how your preparation and race-day conditions differed.
Common questions
How can I use a 5K result to set a marathon goal?
Use the predicted time as a starting point, then compare it with your long-run pace, recent longer races, and marathon preparation. Fueling, weather, and the course also shape your race-day goal.
How is the comparison percentage calculated?
We subtract the predicted second-race time from the actual second-race time, divide by the prediction, and multiply by 100. A positive result means the actual second race was slower than the model prediction.