VO2 Max Calculator
VO2 max is the maximum oxygen your body can use per minute — the standard measure of aerobic fitness and one of the strongest single predictors of long-term health. This calculator estimates it from just your age and resting heart rate, no treadmill test required.
Fill in the fields above to see your result.
How it's calculated
The estimate uses the Uth–Sørensen–Overgaard–Pedersen method, published in 2004: VO2 max ≈ 15.3 × (maximum heart rate ÷ resting heart rate), in ml of oxygen per kg of bodyweight per minute. Your maximum heart rate is predicted from age with the Tanaka formula (208 − 0.7 × age), which replaced the older '220 minus age' rule after a meta-analysis of hundreds of studies showed it fits real populations better, especially past age 40.
Why a heart-rate ratio can stand in for an oxygen measurement: by the Fick principle, oxygen consumption equals cardiac output times oxygen extraction. A lower resting heart rate at a given max generally signals a larger stroke volume — a stronger heart pumping more blood per beat — which is the central adaptation of endurance training. The original study found the ratio method accurate to within roughly ±10% of laboratory testing in trained men. It is an estimate: true VO2 max measurement requires a maximal treadmill or bike test with gas analysis.
For accuracy, measure resting heart rate properly — in the morning, before coffee, after sitting quietly for a few minutes; a wearable's overnight average also works well. Interpreting the result: below 30 ml/kg/min is low, 30-40 fair, 40-50 good, 50-60 very good, and above 60 excellent for most adults (women's reference bands run about 10% lower). VO2 max responds to training within 8-12 weeks of consistent aerobic work, and because resting heart rate falls as fitness improves, re-running this calculator monthly tracks the change without a lab.
Frequently asked questions
What is a good VO2 max?
For most adults: 40-50 ml/kg/min is good, 50-60 very good, 60+ excellent. Elite endurance athletes measure 70-85. Women's reference values run about 10% lower.
How accurate is estimating VO2 max from resting heart rate?
The Uth-Sorensen method validated within roughly ±10% of lab testing. It's an estimate — a maximal test with gas analysis is the only exact measurement.
How do I measure resting heart rate correctly?
First thing in the morning, before caffeine, after a few minutes sitting quietly — or use your wearable's overnight resting average, which is typically very close.
Can I improve my VO2 max?
Yes — consistent aerobic training raises it measurably within 8-12 weeks. Intervals near maximum heart rate drive the fastest gains; easy volume builds the base.
Take it with you
Every calculator, plus workout and macro tracking, in the ElevenSix Fitness app for iPhone.