How to use it
- Step 1Pick a method: resting heart rate ratio, 12-minute run or 1-mile walk.
- Step 2Enter your sex, age and the inputs for that method.
- Step 3Read your estimated VO2 max in ml/kg/min.
Three estimates
- Uth (resting ratio): 15.3 × max HR ÷ resting HR, with max HR from 208 − 0.7 × age.
- Cooper 12-minute run: (meters covered − 504.9) ÷ 44.73.
- Rockport 1-mile walk: 132.853 − 0.0769 × weight (lb) − 0.3877 × age + 6.315 (men) − 3.2649 × time (min) − 0.1565 × finishing heart rate.
How far to trust it
Field estimates can be off by 10% or more compared with a lab treadmill test. Use the same method each time and track your own trend. Check with a clinician before a maximal run test if you have heart disease or symptoms.
More fitness
Common questions
What is a good VO2 max?
It depends on age and sex. Higher is better, and improving your own number matters more than comparing with others.
How can I improve my VO2 max?
Regular aerobic training, including some hard intervals, raises it for most people within weeks to months.
Are smartwatch VO2 max numbers accurate?
They're estimates, often within about 10% for steady runners. Like these tests, they're best for trends.
Does losing weight raise VO2 max?
Because it's measured per kg, losing fat raises the number even if your heart and lungs don't change.