Running tools & calculators
Turn a goal time into a pace, a pace into a finish time, and a recent race into training zones. Free, no sign-up.
Pace and finish time, by distance
| Distance | I have a goal time | I know my pace |
|---|---|---|
| 5K | Pace and splits | Finish time |
| 10K | Pace and splits | Finish time |
| Half marathon | Pace and splits | Finish time |
| Marathon | Pace and splits | Finish time |
Predict and compare
- Race Time PredictorPredict your finish times for different race distances based on a recent performance using the Riegel formula.
- Race Time ComparisonCompare actual race results against Riegel model equivalents across distances.
- VO2 Max EstimatorEstimate VDOT from race time and distance, with an explanation of how it differs from measured VO₂ max.
Train for it
- Training Pace CalculatorCalculate easy and interval references from race-derived VDOT, plus one-hour and marathon equivalents.
- Heart Rate Zone CalculatorCompare maximum-heart-rate and reserve percentage bands, with an optional adult age estimate.
- Elevation Adjusted PaceModel hill energy costs from gain, loss, and uphill and downhill distances under an equal-power assumption.
- Taper CalculatorScale illustrative RaceThere taper templates to your weekly training mileage.
- Calorie Burn CalculatorEstimate gross running energy using published MET values, pace, distance, and body weight.