About the VO2 Max Calculator
A free VO2 max estimator supporting four validated methods — resting heart rate, Cooper 12-minute run, 1.5-mile run, and Rockport 1-mile walk — with age and sex reference ranges.
What it is
VO2 max is the maximum rate at which your body can take in and use oxygen during intense exercise, expressed in millilitres of oxygen per kilogram of bodyweight per minute (ml/kg/min). It is widely used as a marker of cardiovascular fitness — higher values are associated with better aerobic endurance and, in population studies, with long-term health outcomes.
A laboratory graded-exercise test is the gold standard for measuring VO2 max, but it requires specialist equipment and a clinic visit. Field tests estimate it from a measured physical effort instead — with the trade-off that estimates carry a typical error of ±5–10 ml/kg/min. This calculator supports four of the most commonly validated field-test and indirect methods. Enter your result and the tool returns an estimated VO2 max, a category rating against ACSM reference ranges for your age and sex, and your equivalent METs (metabolic equivalents).
All calculations run in your browser — nothing is ever sent to a server or stored.
Key features
Four estimation methods
Choose from the Uth resting heart-rate method, the Cooper 12-minute run, the 1.5-mile run, or the Rockport 1-mile walk test — use whichever suits your situation and fitness level.
Age & sex reference ranges
Results are placed against ACSM normative data for your age group and sex, with six categories from Very Poor to Superior so you can see where your estimate sits.
METs and absolute VO2
Alongside your VO2 max, the calculator shows your equivalent METs. Enter an optional body weight to also see your absolute VO2 in litres per minute.
Metric & imperial units
Switch freely between metric and imperial for distance and body weight inputs. Unit conversions are handled automatically so you can enter values in whichever system you prefer.
How the formulas work
Uth / Tanaka (resting HR)
VO2max = 15.3 × (HRmax ÷ HRrest), where HRmax = 208 − 0.7 × age (Tanaka formula). Requires only resting heart rate and age — no physical test needed, but the least precise of the four methods.
Cooper 12-minute run
VO2max = (distance in metres − 504.9) ÷ 44.73. Run as far as possible in 12 minutes on a flat surface. Metric input in km is converted to metres; imperial input in miles uses 1 mile = 1609.344 m.
1.5-Mile run
VO2max = 3.5 + 483 ÷ time in minutes. Run 1.5 miles as fast as possible and record your time. Enter minutes and seconds; the formula uses total decimal minutes.
Rockport 1-mile walk (Kline)
VO2max = 132.853 − 0.0769 × weight(lb) − 0.3877 × age + 6.315 × sex(1=M,0=F) − 3.2649 × time(min) − 0.1565 × end HR. Walk 1 mile as briskly as possible, record time and immediate post-walk heart rate.
A note on accuracy and safety
Field-test estimates are approximations, not clinical measurements. A typical error of ±5–10 ml/kg/min means your true VO2 max may be meaningfully higher or lower than the estimate. Different methods use different formulas and have different error profiles, so you should not compare scores across methods — track the same test over time to monitor changes in your fitness.
This calculator provides educational fitness estimates only — not medical advice, a clinical assessment, or a substitute for a laboratory graded-exercise test. Field-test VO2 max estimates carry a typical error of ±5–10 ml/kg/min and results differ between methods, so compare the same method over time rather than across methods. The Cooper run, 1.5-mile run, and Rockport walk test require strenuous or maximal effort. Warm up properly before any field test. Do not attempt an all-out test if you have a heart or respiratory condition, feel unwell, or have been advised against vigorous exercise without medical clearance. Stop immediately if you experience chest pain, significant shortness of breath, dizziness, or other symptoms. Consult a qualified health professional before starting an intense training programme or if you have any health concerns.