Pacewise is a calculator for runners. Open it the night before a race, while planning a training block, or when you want to know what the number on your watch really means.
Three tools
1. Pace ↔ speed: enter pace per km, pace per mile, km/h or mph and see every other unit plus finish times for 5K, 10K, half and full marathon.
2. Splits: enter a goal time and get the clock you should hit at every kilometre or mile. Add a negative-split percentage to run the second half quicker.
3. Race predictor: estimate other distances from a recent race using Pete Riegel's 1977 formula, with a 'rough guide' flag when the distances are far apart.
Made to be quick
• Type times the way you say them: 4:30 or 1:45:00.
• Save calculations and load them again later.
• Copy results to paste into notes or a chat.
Results are estimates, not medical advice. No sign-in, no ads, no data collection, and it works offline.
Pace to speed, goal-time splits and race-time prediction for runners.