Race Predictor
One race time, every distance — could you Boston-qualify?
Enter one recent race result and get Riegel-model predictions for every distance from the mile to the marathon — each with pace — plus a Boston Qualifier check against the current BAA age-group standards.
How this is calculated
Methodology & sources
- Prediction formula: Riegel PS. Athletic Records and Human Endurance. American Scientist 1981;69(3):285–90
- Original short form (1.06 exponent): Riegel PS. Time Predicting. Runner's World, August 1977 (print; documented at the link)
- Accuracy in recreational runners: Vickers AJ, Vertosick EA. An empirical study of race times in recreational endurance runners. BMC Sports Sci Med Rehabil 2016;8:26
- Boston qualifying standards: Boston Athletic Association — current qualifying times
Privacy — how your data is handled
All math runs in your browser on your device. Nothing you type is sent to a server,
and saved results live only in this browser's local storage. Tools that use live
public data (food databases, weather) request only what they need to display.
👟 Practical toolkit tip — Simple Pocket Pedometer or Wrist Step Counter
Why it helps: Tracking daily step volume (7,500–10,000 steps/day) prevents subconscious NEAT drop-off when you are in a calorie deficit.
Pro tip: A 15-minute brisk walk after dinner adds ~1,600 steps and blunts post-meal blood glucose spikes.