VO2 max is the most oxygen your body can use at peak effort, in ml/kg/min — the single best lab number for aerobic fitness. You can estimate it in the field two ways: the Cooper test (how far you run in 12 minutes) or a resting-heart-rate formula. This calculator runs both, converts the result to METs, and gives a rough fitness category.
Reviewed: June 20, 2026 · Author: Naveen P N, Founder — AI Calculator · Verified against: the Cooper test and resting-HR VO2 formulas, recomputed in code. General fitness information, not medical advice.
The two methods
The Cooper test is a hard 12-minute effort on a track; the further you go, the higher your estimate. The resting-HR method needs no exercise — it leans on the fact that fitter people have lower resting heart rates. Both are estimates; a graded lab test with gas analysis is the true measurement. Converting to METs (3.5 ml/kg/min each) puts the number in everyday activity-intensity terms.
Worked example — a 2,400 m Cooper run
Scenario: you run 2,400 m in 12 minutes.
A 2,400 m run gives a VO2 max of about 42.4 ml/kg/min — roughly 12 METs and a "good" rating for most adults. Run 2,800 m and it rises to about 51.3 ("excellent"). The resting-HR method for a 30-year-old with a resting rate of 60 estimates about 48.5. The two methods won't match exactly — they measure fitness differently — but both track your progress over time.
Frequently Asked Questions
The most oxygen your body can use at peak effort (ml/kg/min) — the core aerobic-fitness number. Active adults ≈ 35–50.
(metres in 12 min − 504.9) ÷ 44.73. 2,400 m → ≈ 42.4; 2,800 m → ≈ 51.3.
Yes: 15.3 × (maxHR ÷ restHR), maxHR = 220 − age. Age 30, rest 60 → ≈ 48.5. Less precise, no running.
Broadly: <30 poor, 40–50 good, 50–60 excellent, >60 superior. Varies by age and sex; compare within your group.
1 MET = 3.5 ml/kg/min. METs = VO2 max ÷ 3.5. So 42 ml/kg/min ≈ 12 METs.