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
PRESZN 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.
PRESZN is in private beta — ask the friend who sent you this for a TestFlight invite.
The 12-week running programQuestions
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 30-minute sessions.