How the race predictor works
The calculator uses the Riegel formula: T2 = T1 × (D2 / D1)^1.06. It converts a known performance into equivalent times at other distances, assuming similar training and terrain.
Race Time Predictor
Enter one recent result and see your equivalent times from 800 m to the marathon.
Do you train with a goal?
MiRitmo is building a new way to analyse your training, your reps and your progress.
JOIN MIRITMO ÍSLANDHow accurate is it?
Predictions are most reliable within a factor of three or four in distance. Predicting a marathon from a 1500 m result will overestimate your fitness unless you have the endurance base to match: long-distance results depend on volume, fuelling and pacing, not only on speed.
Using the prediction to train
Take the predicted time as the ceiling of what your current speed allows, then check it against your training. If your race is longer than the reference, add specific long-distance work before trusting the number.
FAQ
- How do I predict my marathon time?
- Enter a recent half marathon or 10 km result. The predictor applies the Riegel model to estimate your equivalent marathon time, assuming marathon-specific endurance work.
- What is the Riegel formula?
- T2 = T1 × (D2 / D1)^1.06, where T1 is a known time over distance D1 and T2 is the predicted time over distance D2.
- What is VDOT?
- VDOT is a single number that summarises the aerobic fitness a race performance implies. It is used to derive consistent training paces.