VO2 Max / VDOT Calculator
Enter a recent race time and get your aerobic fitness score (VO2 max), VDOT number, predicted times at every distance, and pace zones calibrated to your threshold. Uses the Daniels-Gilbert formula and Riegel race prediction model.
Your fitness test
Choose how you want to calculate your VO2 max.
The most common method: any race between 5K and marathon gives a reliable VDOT.
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Download your VO2 max, equivalent times, and training paces as a PDF plus weekly training tips.
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What is VDOT? VDOT is Jack Daniels' shorthand for the maximal oxygen uptake (VO2 max) implied by your race performance. It is numerically identical to the VO2 max value this calculator returns. A higher VDOT means a higher aerobic ceiling: the ability to sustain faster paces at the same relative effort.
VDOT-based training uses your score to set all intensity zones. Because it comes from an actual race rather than a lab test, it captures how efficiently you use oxygen, not just your raw aerobic capacity. For context: elite male marathon runners typically score 70-80+; a solid age-group triathlete is usually in the 45-55 range.
To adjust paces for race-day heat or altitude, use the Pace Adjustment Calculator.
How this calculator works
Race-time method: Daniels-Gilbert formula. Velocity (m/min) from distance and time is substituted into VO2(v) = -4.60 + 0.182258v + 0.000104v squared. The fraction of VO2 max used at that race pace is estimated by pctVO2max(t) = 0.8 + 0.1894393 * e^(-0.012778t) + 0.2989558 * e^(-0.1932605t), where t is race time in minutes. VO2 max = VO2(v) / pctVO2max(t). Cooper method: VO2 max = (distance in metres minus 504.9) divided by 44.73 (Cooper 1968). Threshold velocity is solved at 88% VO2 max. Equivalent race times use the Riegel formula (exponent 1.06). Training paces are derived from threshold pace by applying the same zone fractions as the Training Zones Calculator.
Assumptions
- • The race was run at a genuine, well-paced maximal effort
- • Cooper test: flat measured surface, exactly 12 minutes
- • Standard Daniels-Gilbert coefficients apply (healthy trained runner)
Limitations
- • Riegel marathon prediction is often optimistic for athletes without marathon-specific training
- • Cooper test VO2 max is field-based and carries more error than a lab VO2 max
- • Both methods assume the runner is not altitude-acclimatised above sea level
Who this is for
- • Runners and triathletes setting evidence-based training paces from a recent race
- • Athletes who want a fitness benchmark from a race or field test
Who this is not for
- • Athletes who need a clinically measured VO2 max (lab test required)
- • Predicting performance on a course with significant elevation (no grade correction)