Running pace calculator
See how your pace compares to threshold pace, what load the session generates and what your critical speed is.
Everything is computed in your browser — the values you enter are never sent or stored.
Result
- Session pace
- 5:00 min/km
- run_IF
- 0.80
- Intensity band
- easy, aerobic base
- Load (runStress)
- 64
- Speed
- 12.0 km/h
Training paces relative to threshold
| Type | run_IF | Pace |
|---|---|---|
| Recovery | 0,75 | 5:20 min/km |
| Easy (Z2) | 0,85 | 4:42 min/km |
| Steady | 0,95 | 4:13 min/km |
| Threshold | 1,00 | 4:00 min/km |
| Above threshold | 1,05 | 3:49 min/km |
For reference: an athlete running 1200 m in 5:00 and 3000 m in 13:00 has a critical speed of 3.8 m/s. On hills and trails pace stops being meaningful — steer by heart rate or perceived effort instead.
How we calculate this
- run_IF = threshold pace / actual pace
- runStress = hours × run_IF² × 100
- CS = (D2 − D1) / (T2 − T1)
The formulas come from the app’s domain specification and are covered by unit tests. The same code powers zones inside the app.
Want these numbers to feed your plan automatically?
In the app, zones update after every test and the plan adapts to your data and how you feel.
This calculator is informational and does not replace a doctor, physiotherapist or coach. Results based on population formulas are estimates, not measurements. Read the full disclaimer →