Frequently Asked Questions
How does the race time predictor work?
The calculator applies the Riegel formula to a known race result, adjusting predicted time as distance increases. It assumes your endurance and preparation are appropriate for the target distance.
How accurate are race time predictions?
Predictions are most useful when based on a recent, all-out result over a similar distance. Course profile, weather, fatigue, fueling and distance-specific training can all change the actual result.
Can a 5K time predict a marathon time?
A 5K result can provide a mathematical estimate, but marathon performance depends much more on aerobic endurance, long runs, pacing and fueling. Treat the result as a goal range rather than a guarantee.