VO2 Max Calculator (Cooper 12-minute run)

Understanding the VO2 max calculator (Cooper test) — concept and principle

VO2 max is the maximum rate at which your body can take up and use oxygen during exercise, expressed in millilitres of oxygen per kilogram of bodyweight per minute (mL/kg/min). It is one of the best single measures of aerobic fitness. The Cooper test estimates it without a lab: you run as far as you can in 12 minutes, and the distance is converted to VO2 max with Kenneth Cooper's 1968 equation.

Distance in 12 minutes turns into an estimate of aerobic capacity — a field estimate, not a lab test.

How it is calculated

VO2 max = (distance − 504.9) ÷ 44.73

Distance: metres covered in exactly 12 minutes, ideally on a 400 m track.
Result: estimated VO2 max in mL/kg/min.

Each additional 44.73 m in 12 minutes adds about 1 mL/kg/min to the estimate.

The principle

Running at a steady pace costs a fairly predictable amount of oxygen per kilogram for each metre covered. A 12-minute all-out effort is long enough that most energy comes from aerobic metabolism, so the average speed you can hold reflects your maximal oxygen uptake. Cooper measured VO2 max on a treadmill in a group of US Air Force men and found a strong linear relationship with their 12-minute distance; the equation is the straight line fitted to that data. Like any regression, it works best for people similar to the original sample and assumes a well-paced, maximal effort.

Worked example

Input: 2,600 m in 12 minutes.
2,600 − 504.9 = 2,095.1.
2,095.1 ÷ 44.73 ≈ 46.84 mL/kg/min.

Each point is the calculator re-run with only “Distance in 12 minutes (m)” changed; the gold point is the default example. Change the inputs above and this chart follows your numbers.

Distance in 12 minutes (m)	VO2 max (mL/kg/min)
650	3.24
1,300	17.78
1,950	32.31
2,600	46.84
3,250	61.37
3,900	75.9
5,200	104.97

How to read the result

Higher is better, and values naturally decline with age and are on average lower in women than in men. Untrained adults often fall somewhere in the 30s to low 40s, while elite endurance athletes can exceed 70 mL/kg/min. Compare your number with age- and sex-specific norm tables, such as those in the ACSM guidelines, or simply with your own earlier tests. Retesting every 8–12 weeks under similar conditions shows whether your training is working.

Common mistakes

Starting too fast and walking in the second half, which lowers the distance.
Measuring distance with GPS on a winding route; a track is far more accurate.
Testing in heat, wind or after a hard training day.
Treating the estimate as a lab-grade measurement.

Keep in mind: This is a field estimate, not a medical assessment. A maximal 12-minute run is very demanding: if you are inactive, older, have heart or lung problems or any symptoms on exertion, get medical clearance first and consider a walking test instead.

Frequently asked questions

What is a good VO2 max?

It depends strongly on age and sex. Compare with published norm tables for your group; being above average for your age is a good sign for health and performance.

How accurate is the Cooper test?

In fit, well-motivated runners it correlates well with lab tests, but individual errors of several mL/kg/min are common, especially with poor pacing.

Can I do the test on a treadmill?

You can, but set a 1% incline to mimic outdoor running and note that results are less comparable with track tests.

Sources: Cooper K. H., A means of assessing maximal oxygen intake: correlation between field and treadmill testing, JAMA, 1968 · American College of Sports Medicine, ACSM's Guidelines for Exercise Testing and Prescription

Checked 8 Nov 2026. Cooper, JAMA 1968.

Your numbers