VO2 Max Estimator (Resting Heart Rate Method)
Estimate aerobic fitness (VO2 max) from age and resting heart rate.
What this calculates
VO2 max measures how much oxygen your body can use during intense exercise — the single best lab metric for cardiovascular fitness and longevity. This calculator uses the Uth-Sørensen-Overgaard-Pedersen (UTH) formula, which estimates VO2 max from age-predicted max HR and resting HR (no test needed). Accuracy is ±10-15%.
Formula & how it works
VO2 max ≈ 15.3 × (HRmax / HRrest), where HRmax = 220 − age. Result in ml/kg/min.
Worked example
Age 35, resting HR 55. HRmax = 185. VO2 max ≈ 15.3 × (185/55) = 51.5 ml/kg/min — excellent for age.
Frequently asked questions
How accurate is this?
±10-15%. Lab-grade is ±2%. Cooper test or 1.5-mile run estimates are tighter than this — but those need exercise.
What's a good number?
30s-40s: men 40-50 average, 55+ excellent; women 32-38 average, 45+ excellent. VO2 max naturally declines ~10% per decade after 30.
Resting HR accuracy?
Measure first thing on waking, lying still, 60 seconds counted. Average 3-5 days.
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