Cooper Test Calculator (12-Minute Run)

The Cooper test is a 12-minute run for distance, and the distance converts straight into an estimated VO2 max. Kenneth Cooper, a physician with the U.S. Air Force, published the field test in JAMA in 1968 after correlating it against treadmill measurement, and it is still one of the most widely used field assessments in the world. Enter your distance in meters:

Miles to meters, and to an estimate

American tracks are metric — a standard outdoor lane is 400 m, so a mile is four laps plus about nine meters. If your watch reports miles, use this:

Distance	Meters	Estimated VO2 max
1.00 mile	1,609 m	24.7 mL/kg/min
1.25 miles	2,012 m	33.7 mL/kg/min
1.50 miles	2,414 m	42.7 mL/kg/min
1.75 miles	2,816 m	51.7 mL/kg/min
2.00 miles	3,219 m	60.7 mL/kg/min

Every extra 100 meters is worth about 2.2 points of estimated VO2 max, which is a useful sense of scale: pacing errors and a windy day are worth real points here.

The formula

VO2 max = (distance in meters − 504.9) ÷ 44.73

Worked through for 2,400 m — a common round target, just under a mile and a half: (2,400 − 504.9) ÷ 44.73 = 1,895.1 ÷ 44.73 = 42.4 mL/kg/min.

Notice what is not in the equation: your age, your sex, your weight. Cooper’s test converts a single distance and nothing else, which is what makes it so easy to administer and so blunt as an individual assessment. Two people covering the same distance get the same estimate whether they are 20 or 60.

That is also why this page does not print a “good for your age” table. Age-graded Cooper charts are everywhere, but they are secondary reworkings whose underlying data is rarely documented, and publishing a number we could not trace is worse than publishing none. For a fitness verdict, the VO2 max calculator at least states what its bands are and how coarse they are.

Running the test properly

1. Pick a measured course. A 400 m track is ideal because you can count laps and read partial distance off the lane markings. GPS on a winding road will flatter or rob you.
2. Warm up for at least ten minutes, including a few faster strides. A cold start costs distance in the first two minutes and those meters count the same as the last ones.
3. Run for exactly 12 minutes, covering as much ground as you can. Walking when you need to is allowed and does not invalidate the test.
4. Mark where you are at the whistle and measure the total distance.

The single biggest source of error is pacing. Going out too fast is the classic way to record a worse result than your fitness deserves; an even effort, finishing hard, gets the most out of the 12 minutes. Heat, wind, altitude, footwear and how motivated you feel that morning all move the number too, so compare like with like across attempts.

Before you attempt it

This is a maximal effort test. If you are sedentary, returning from a long break, or have any cardiovascular condition, get medical clearance before running it — and consider the Rockport walk test calculator instead, which reaches a similar estimate from a fast one-mile walk. Knowing your training ranges first also helps: the Karvonen formula calculator builds them from your resting pulse, and the max heart rate calculator gives the ceiling they are built on.

This content is informational and does not replace medical evaluation before maximal exercise testing.