Run the Numbers
The runner's toolkit — built for calculating, not tracking. Pace, splits, predictions, and workouts all in sync.

Pick a distance or enter your own, set a finish time, and instantly see your pace, speed, and converted units.
Generate per-km or per-mile splits with even, negative, or positive strategies. Share a race card with friends.
Use the Riegel formula to predict finish times across distances — from 1 mile to 50K. Adjust for fitness and see your age grade.
Choose from smart templates — intervals, tempo, long run, speed work — with paces derived from your target race time.
Pace conversion, training zones, treadmill speed calculator, Boston Qualifier checker, race comparison, and more.
Log your personal records and tap any PR to instantly populate your pace, splits, and predictions.





RunSolver is completely free with no ads, no accounts, and no tracking. All calculations happen instantly on your device.