VO₂ Max Calculator

The VO₂ max formula

Uth et al. (2004): VO₂ max ≈ 15.3 × (HR_max ÷ HR_rest), with HR_max = 220 − age. A lower resting heart rate raises the estimate, reflecting a stronger, more efficient heart. The method works because endurance training lowers resting heart rate, so the ratio of maximum to resting pulse tracks aerobic fitness reasonably well across a population — though for any one person the rough "220 − age" rule can be off by 10–12 bpm, which is the main source of error here.

What VO₂ max tells you

VO₂ max is the maximum rate at which your body can take in, transport and use oxygen during all-out exercise, measured in millilitres of oxygen per kilogram of body weight per minute. It is the best single number for cardiorespiratory fitness, and higher values are consistently linked with better endurance performance and lower long-term health risk. Divide it by 3.5 to read it in METs — a VO₂ max of 42 ml/kg/min is 12 METs, or twelve times your resting energy use — which is how the intensity of activities is usually rated.

For most people VO₂ max responds to training within weeks. A mix of steady endurance sessions and shorter high-intensity intervals raises it the fastest, and because that training also lowers resting heart rate, the resting-pulse estimate above should improve as your fitness does. Age and genetics set the ceiling, but there is usually plenty of room to move within it. For a performance-based figure, retest with the Cooper 12-minute run or the Rockport one-mile walk rather than resting pulse alone.

This is a reference tool, not a diagnosis or medical advice. Results depend on the laboratory, assay and clinical context, and reference intervals vary between labs and by age and sex — always read your result against the range printed on your own report and discuss it with a qualified healthcare professional.