Running pace calculator
Pace per kilometre and per mile from any run — with race-time predictions for 5K to marathon at your current fitness.
Pace per km
5:00
Pace per mile
8:03
Race predictions at this fitness (Riegel)
| Distance | Predicted time | Pace/km |
|---|---|---|
| 1 km | 4:32 | 4:32 |
| 1 mile | 7:31 | 4:40 |
| 5K | 25:00 | 5:00 |
| 10K | 52:07 | 5:13 |
| Half marathon | 1:55:00 | 5:27 |
| Marathon | 3:59:47 | 5:41 |
Predictions assume equivalent training for the target distance.
Track every run from your wrist
PRE SZN tracks your running on the Apple Watch — GPS, heart rate, sprint distance and high-speed running — and folds it into the same readiness picture as your lifting. Built for athletes who run fast, not just far.
Questions
How is running pace calculated?
Pace is time divided by distance — a 25:00 5K is 25 minutes over 5 km, so 5:00 per km (about 8:03 per mile). This calculator does both conversions from any distance and time.
How does the race time predictor work?
It uses Riegel's formula: predicted time = your time × (target distance ÷ your distance) ^ 1.06. It is remarkably accurate between distances you have actually trained for, and optimistic for distances you have not.
What pace should I train at?
Most quality running programs prescribe a mix: easy running well below race pace, and short fast work well above it. For field-sport athletes, PRE SZN Running skips the mileage entirely — speed development, shuttles and speed endurance in 40-minute sessions.