VO₂max from Resting Heart Rate Calculator

About this calculator

This calculator estimates VO₂max — the maximum rate at which your body can consume oxygen during intense exercise, and the gold-standard measure of aerobic fitness — using the Uth-Sørensen-Overgaard-Pedersen formula: VO₂max = 15.3 × (HRmax / HRrest). HRmax is typically estimated as 220 minus age, and HRrest is your resting heart rate measured first thing in the morning before getting out of bed.

The logic behind the formula is that a lower resting heart rate relative to your maximum heart rate generally reflects a more efficient, better-conditioned cardiovascular system, since a fitter heart pumps more blood per beat and doesn't need to beat as often at rest. It was derived by comparing this simple ratio against lab-measured VO₂max values in a study of Danish adults.

Runners, cyclists, and fitness trackers use this method as a quick, no-equipment alternative to a treadmill gas-exchange test — it is far less precise than direct laboratory measurement, but it is useful for tracking whether your fitness is trending up or down over time, especially since resting heart rate is easy to measure daily.