VO2 max estimator
Estimate aerobic fitness from a Cooper 12-minute run or from your maximum and resting heart rates.
A clear answer. Here’s how.
Two field methods, both returning millilitres of oxygen per kilogram per minute. Cooper’s 12-minute test (1968): VO2 max = (metres covered − 504.9) ÷ 44.73. The heart-rate ratio method of Uth and colleagues (2004): VO2 max = 15.3 × maximum heart rate ÷ resting heart rate. Equivalent METs divide by 3.5 ml/kg/min. These are population-level regressions, so an individual can be several units out.
How this is checked
2 reference checks passed These 2 cases were run when this page was built, on 20 October 2026, and all reproduce within the stated tolerance. The same cases are part of the automated tests that run on every change to Toolmoz. Engine version 1.
See the checks and where each expected answer comes from
Case 1
- Inputs
- Method cooperDistance covered in 12 minutes (metres) 2400
- Expected, and what Toolmoz gave
- Estimated VO2 max (ml/kg/min) expected 42.3675, Toolmoz 42.36753856472166Equivalent METs expected 12.105, Toolmoz 12.105011018491904
- Where the expected answer comes from
- (2400 − 504.9) ÷ 44.73 = 42.3675 and 42.3675 ÷ 3.5 = 12.105 (hand calculation)
- Allowed difference
- ±0.001
Case 2
- Inputs
- Method hrMaximum heart rate (bpm) 190Resting heart rate (bpm) 60
- Expected, and what Toolmoz gave
- Estimated VO2 max (ml/kg/min) expected 48.45, Toolmoz 48.45
- Where the expected answer comes from
- 15.3 × 190 ÷ 60 = 2907 ÷ 60 = 48.45 (hand calculation)
- Allowed difference
- ±1e-9
What this shows: the engine reproduces independently worked values for these cases. It does not prove every possible input is right. To test an answer you were given, see how to check a number; to see what is and is not checked across Toolmoz, see the accuracy ledger.
See a worked example
Worked example
A fixed demonstration, separate from the values you enter above.
- Method
- Cooper 12-minute run
- Distance covered in 12 minutes (metres)
- 2400
Example result
- Estimated VO2 max (ml/kg/min)
- 42.4
- Equivalent METs
- 12.1
- Method
- Cooper 12-minute run: (distance in metres − 504.9) ÷ 44.73
An estimate, not a lab measurement: field-test formulas are typically several ml/kg/min out for an individual. The Cooper test needs a maximal, well-paced 12-minute effort on a flat course; the heart-rate ratio needs a true maximum and a resting rate taken at rest.