About this tool
The VDOT & Equivalent Race-Time Calculator takes one race result and predicts your equivalent finish times across the common racing distances, using the Daniels/Gilbert VDOT model. It first computes your VDOT fitness score, then finds the time at each other distance that yields the same VDOT. Everything is computed locally in your browser.
VDOT is derived from the race distance D (metres) and time t (minutes): v = D ÷ t; VO₂ = −4.60 + 0.182258·v + 0.000104·v²; %VO₂max = 0.8 + 0.1894393·e^(−0.012778·t) + 0.2989558·e^(−0.1932605·t); VDOT = VO₂ ÷ %VO₂max. To predict another distance, the tool searches for the time whose VDOT matches yours: because VDOT falls as the time for a fixed distance grows, it solves this by bisection between 1 and 600 minutes for each target.
Equivalent times are shown for the mile, 3K, 5K, 10K, 15K, half marathon and marathon, alongside your VDOT number. This is the Daniels/Gilbert equivalence — distinct from the simpler Riegel exponent predictor — and assumes comparable fitness, pacing and course conditions across distances. Use it to set realistic goals and spot which distances suit your current form. It is a performance guide, not medical advice.