This VO2 max calculator estimates your maximal oxygen uptake, the most widely used measure of aerobic fitness. Choose the test that suits you: a no-exercise estimate from resting heart rate, the Cooper 12-minute run, or the Rockport 1-mile walk.
What is VO2 max?
VO2 max is the maximum amount of oxygen your body can use during intense exercise, measured in milliliters per kilogram of body weight per minute (ml/kg/min). Higher values mean better cardiovascular fitness, and higher fitness is linked with lower risk of heart disease and early death.
Test formulas
- Resting heart rate (Uth): VO2 max = 15.3 × max heart rate ÷ resting heart rate, with max heart rate = 208 − 0.7 × age.
- Cooper 12-minute run: VO2 max = (meters run − 504.9) ÷ 44.73.
- Rockport 1-mile walk: 132.853 − 0.0769 × weight (lb) − 0.3877 × age + 6.315 × (1 for men) − 3.2649 × time (min) − 0.1565 × finishing heart rate.
Worked example
A 35-year-old with a resting heart rate of 62 has an estimated maximum heart rate of 183.5, giving a VO2 max of about 45 ml/kg/min. Running 2,400 meters in the Cooper test gives about 42.4 ml/kg/min.
How to improve VO2 max
- Build an aerobic base with regular easy cardio, such as Zone 2 training.
- Add one or two sessions a week of intervals, such as 4 × 4 minutes hard with recovery between.
- Be consistent; most people see improvement within 6 to 12 weeks.
Frequently asked questions
What is a good VO2 max?
It depends on age and sex. Values typically fall with age, and well-trained endurance athletes often have much higher values than the general population. Compare your result with your own past tests.
How accurate are VO2 max estimates?
Field tests and formulas can be several points off. A lab test with gas analysis is the most accurate.
Is my smartwatch VO2 max accurate?
Watches use heart rate and pace data and can be reasonably close for runners, but they are estimates too.
Which test should I use?
Use the resting heart rate method if you cannot exercise hard, the Rockport walk if you are less fit, and the Cooper run if you are used to running.
Related calculators
Last reviewed: October 2026. For information only; not medical advice. Talk to a doctor about any health concerns.