VO2 Max Estimate Calculator — What Is Your Aerobic Fitness Level?

VO2 max — maximal oxygen uptake — is the gold standard measure of aerobic fitness and one of the strongest predictors of all-cause mortality in population studies. It represents the maximum rate at which your cardiovascular and muscular systems can use oxygen during intense exercise. Higher VO2 max means a more efficient heart, better oxygen delivery, and a larger aerobic engine. You don't need a lab to get a useful estimate. This calculator offers four validated estimation methods: the Cooper 12-minute run test, the resting heart rate method (Uth-Sørensen formula), the submaximal Åstrand exercise protocol, and pace-based estimation for runners. Each method has different accuracy profiles — the Cooper test is most accurate if you can run at maximal effort; the resting HR method is easiest for people who can't do maximal exercise testing. Once estimated, your VO2 max is compared to population norms by age and sex to give a percentile ranking and category (Below Average through Elite). The calculator also outputs your fitness age — the age at which your VO2 max would be average — which can be powerfully motivating when it's younger than your actual age. Heart rate training zones, race time predictions, and improvement methods are all derived from your estimated VO2 max, making this a complete aerobic fitness assessment tool.