Running Pace Calculator — min/km, min/mile & Finish Times
Enter a distance and time to get your pace per km and per mile, speed, and predicted 5K, 10K, half and full marathon finish times. Free, in your browser.
Predicted finish times
- 5Keven pace 25:00 · Riegel 23:59
- 10Keven pace 50:00 · Riegel 50:00
- Halfeven pace 1:45:29 · Riegel 1:50:19
- Marathoneven pace 3:30:59 · Riegel 3:50:01
Bold is Riegel’s prediction, T₂ = T₁ × (D₂/D₁)^1.06, which allows for the slowing that a longer race brings. Grey is the pace you entered held flat over the distance.
🔒 Calculated in your browser — nothing is uploaded.
Find your running pace
Enter the distance you ran (in km or miles) and the time it took, and see your pace per kilometre and per mile plus your speed in km/h and mph. Use the race buttons to drop in a 5K, 10K, half or full marathon distance instantly.
Predicted finish times
Each standard race distance gets two figures. One is your entered pace held flat — the answer to "what marathon time is this pace?". Beside it is a prediction from Riegel's formula, T₂ = T₁ × (D₂/D₁)^1.06, which allows for the slowing a longer race brings: from a 25:00 5K the flat line says a 3:30:59 marathon and Riegel says 3:59:47. Everything is calculated locally in your browser.
Frequently asked questions
How is running pace calculated?
Pace = time ÷ distance. Ten kilometres in 50 minutes is a pace of 5:00 per km (about 8:03 per mile).
Are the marathon predictions accurate?
Two numbers are shown per race. The even-pace one is exact arithmetic — your pace times the distance — and is optimistic for anything much longer than what you ran. The bold one is Riegel’s formula, the standard race predictor, which allows for that slowing; it assumes you have trained for the longer distance and is least reliable under about 3.5 minutes or over about 4 hours.
Can I switch between km and miles?
Yes. Pick the distance unit you entered; pace is always shown per km and per mile side by side.