How this calculator works
VO2 max is the most oxygen your body can use in one minute of all-out effort, per kilogram of body weight.
Labs measure it directly with a mask while you exercise on a treadmill. This calculator estimates it from a field test, with formulas from published studies.
Your estimate then goes on the VO2 max by age chart, built from 16,278 treadmill tests in 34 US labs. That gives you a percentile for your age and sex. It also gives you a “typical age”: the age whose median score matches yours.
Which test should you pick?
Pick the hardest test you can do safely. The resting heart rate method is the easiest, but its formula comes from the smallest study.
| Test | Effort | What you need | Best for |
|---|---|---|---|
| 1-mile walk | A flat, measured mile and your pulse at the finish. | Women, regular walkers and anyone new to fitness tests. | |
| 12-minute run | A track or measured route and a stopwatch. | Runners used to hard effort. | |
| Resting heart rate | Your age and resting pulse. | An easy first check, or when hard effort isn’t safe for you yet. |
Have a number from a lab test or a watch? Enter it directly, and the calculator shows where you stand.
How to do each test
1-mile walk
- Warm up for about five minutes.
- Walk a flat, measured mile as fast as you can without running. Four laps of a 400-meter track come close.
- Right at the finish, take your pulse or read it from a chest strap or watch. Note your time too.
12-minute run
- Warm up for about ten minutes.
- On a track or measured route, cover as much distance as you can in 12 minutes.
- Run when you can and walk when you need to.
- Note the distance you covered.
Resting heart rate
- In the morning, sit quietly for five minutes.
- Count your pulse for 60 seconds.
- Repeat on three mornings and average the numbers.
How accurate is your estimate?
Each formula comes from a different group of people.
The 1-mile walk formula comes from a study of 343 healthy men and women aged 30 to 69.
The 12-minute run formula comes from a study of 115 US Air Force men aged 17 to 52 (average 22). Their distance tracked closely with lab results (r = 0.897). The study said accuracy in older people was not yet known, though early data up to age 50 looked good.
The resting heart rate formula comes from a study of 46 well-trained men aged 21 to 51. With top heart rate predicted from age, as here, its typical error was about 4.7 ml/kg/min.
That age formula (208 minus 0.7 times your age) comes from a review of 351 studies, with no difference between men and women.
Two of the three formulas were built only on men. For women, the 1-mile walk is the best-founded choice.
What your result means
Your percentile shows where you rank among people of your age and sex who took a lab test. At the 65th percentile, you scored higher than 65 of every 100.
If your typical age is below your real age, your fitness is ahead of your years. If it’s above, you have room to improve.
The VO2 max by age chart shows the full norms.
Is the test safe for you?
The walk and the run take real effort. Check with your doctor first if you have heart disease, get chest pain or dizziness when you exercise, or haven’t been active in a long time.
Stop right away if you feel chest pain, faintness or unusual shortness of breath.
The resting heart rate method needs no exercise.