Race Time Predictor

This calculator uses the VDOT formula developed by legendary coach Dr. Jack Daniels. VDOT is a measure of your running fitness that accounts for both your VO₂max and running economy. Unlike simple formulas, it uses empirically validated data from thousands of runners.

The algorithm calculates your oxygen cost at race pace and the percentage of VO₂max you can sustain for a given duration. Shorter races allow higher intensity, while longer races require more sustainable effort.

Predictions are most accurate for distances between 1500m and marathon when you're properly trained for both distances. Marathon predictions may be optimistic if you haven't done specific long-distance training.