VO2 Max Calculator — Estimate from Race Results

This calculator estimates VO2 max from a race result — the maximum rate at which your body can use oxygen during intense exercise. Enter the distance and finish time from a recent race or hard time trial to get an estimate in ml/kg/min.

The calculation uses Jack Daniels' race formula: it first estimates the oxygen cost of your race pace, then adjusts for how long you sustained that effort. Shorter, faster races (for example, a 25-minute 5K) typically produce more reliable estimates than very long events, where pacing and fueling play a larger role.

VO2 max is one useful marker of aerobic fitness, but it is not the whole picture. Running economy, lactate threshold, and race-day conditions all affect performance. Treat this estimate as a training reference — a 50-minute 10K and a 1:45 half marathon may give slightly different results even for the same runner.

For the most accurate estimate, use a recent all-out effort at a distance between about 3 km and 21 km. Easy training runs, group races with conservative pacing, or results from several months ago may not reflect your current fitness.