VO2max from Resting Heart Rate Calculator

About this calculator

The Uth–Sørensen–Overgaard–Pedersen (Uth–Sørensen) formula estimates VO2max — the maximum rate at which your body can consume oxygen during exercise, and the gold-standard marker of aerobic fitness — from the simple ratio of maximum to resting heart rate: VO2max = 15.3 × (HRmax / HRrest). It was derived by correlating this heart rate ratio against lab-measured VO2max in trained cyclists, and it trades some accuracy for the ability to estimate fitness from two pulse readings instead of a treadmill or metabolic cart.

Runners, cyclists and fitness trackers use this shortcut when they want a rough aerobic-fitness number without booking a graded exercise test, and coaches use falling resting heart rate over weeks of training as an indirect sign that VO2max is improving. Because it only needs resting and maximum pulse, it is popular in wearables and self-coached training logs, though it is less precise than a direct lab test or a field time-trial-based estimate.

This calculator takes your resting heart rate and maximum heart rate and applies the Uth–Sørensen formula to return an estimated VO2max in ml/kg/min.