One 12-minute run. One number to rule them all.
Type the distance you covered in a 12-minute all-out run (the classic Cooper test from 1968). We return your VO₂max in ml/kg/min, rate it against age-and-gender norms, and tell you the rough percentile you sit in.
Kenneth Cooper, an Air Force exercise physiologist, validated this test in 1968 against direct lab VO₂max measurements on thousands of military personnel. Twelve minutes is long enough to push past anaerobic contributions and short enough to be all-out aerobic — a near-pure VO₂max effort. The original Cooper formula VO₂max = (d − 504.9) / 44.73 (with d in metres) tracks lab values to within ~3 ml/kg/min for trained adults.
Pick a flat 400 m track or treadmill. Warm up 15 minutes including 3 × 1 min hard. Start a stopwatch and run as far as you can in exactly 12 minutes. Pace it like a 5K — slightly aggressive first 3 minutes, settle, then push the last 90 seconds. Cool down. Re-test every 6-8 weeks; expect your VO₂max to improve fastest in the first season of structured training.
The formulas and ranges above are grounded in the following peer-reviewed literature.
The original 12-minute run test paper. Our formula VO₂max = (distance_m − 504.9) / 44.73 is from this study.
Read paperBetter-validated alternative to the Cooper test (the "beep test"). If you have access to a 20-m shuttle, it produces tighter VO₂max estimates.
Read paperSource for the gendered age-bracket fitness rating tables (Excellent / Good / Average / Poor).
View bookFor trained runners on flat terrain in cool conditions, the Cooper formula tracks lab VO₂max to within ±3 ml/kg/min — close enough for training decisions. Accuracy degrades for very fit runners (it underestimates) and sedentary subjects (it overestimates). Wind and heat can cost 100-200 m of distance, which translates to roughly 2-4 ml/kg/min, so re-test in similar conditions.
We compare your number to Cooper’s age and gender brackets — for example, a 30-year-old man hitting 50 ml/kg/min lands in the "Excellent" bracket. The percentile estimate ("better than ~75% of men your age") is derived from those same brackets and gives a fast intuition for how your aerobic engine compares with the general population.
VDOT (Jack Daniels) is essentially a race-paced VO₂max equivalent. We surface an approximate VDOT alongside your VO₂max so you can plug it into the VDOT calculator for training paces. As a rule of thumb, a VO₂max of 50 corresponds roughly to a 19:00 5K and a 3:30 marathon for trained runners.
Yes — consistent aerobic training raises VO₂max 10-20% in the first 6-12 months for previously sedentary adults. Trained athletes plateau closer to genetic ceilings, but VO₂max-targeted intervals (3-5 minutes at 95-100% VO₂max effort, with full recovery) remain the most effective tool to push the ceiling higher.
Watches estimate VO₂max from sub-maximal heart rate during easy runs — clever but indirect. The Cooper test directly measures your aerobic ceiling under all-out conditions. Numbers from both methods should land within ±3-5 ml/kg/min of each other; if yours diverge more than that, the Cooper test is the more honest benchmark.
Track is gold standard — flat, calibrated, no wind. Treadmill works if it’s set to 1% incline (the standard correction for indoor running’s lack of air resistance) and you watch the distance counter, not the time. Avoid roads with traffic, hills or wind: each variable degrades the result.