VO2 Max Calculator — Estimate Aerobic Fitness from a 12-minute Run or Heart Rate

How to use the VO2 max calculator

1. Choose the Method: Cooper 12-minute run or Heart-rate ratio.
2. For Cooper, enter the Distance covered in 12 minutes in metres.
3. For heart-rate ratio, enter your Age, your Resting heart rate, and your Measured maximum heart rate, or 0 to estimate it from age.
4. Read your estimated VO2 max in ml/kg/min, with the distance and speed or the heart rates used.

What it does and when to use it

VO2 max is a common measure of aerobic fitness. A lab test is the accurate way to get it, but most people do not have one handy. The two field methods here give a rough number you can track as you train. Use it to see whether your fitness is moving in the right direction, alongside the Heart Rate Zone Calculator for training intensity and the Pace Calculator for race targets.

How it works

Cooper 12-minute run: VO2 max = (distance in metres − 504.9) ÷ 44.73. This is the form of Cooper’s regression that is widely used. The 1968 JAMA abstract confirms the study design and the 0.897 correlation, but not these constants, which is why this page is held back from search results until they are checked against the full paper.

Heart-rate ratio (Uth et al., 2004): VO2 max = 15.3 × maximum heart rate ÷ resting heart rate. The factor 15.3 was measured in a group of well-trained men. If you enter 0 for maximum heart rate, the calculator uses 220 − age, which makes the estimate less accurate.

Worked examples

Cooper test. Running 2,400 m in 12 minutes (an average of 12 km/h) gives (2,400 − 504.9) ÷ 44.73: Estimated VO₂ max: 42.37 ml/kg/min.

Heart-rate ratio. A resting heart rate of 60 and a measured maximum of 180 give a ratio of 3, and 15.3 × 3: Estimated VO₂ max: 45.9 ml/kg/min. For a 40-year-old, entering 0 for maximum gives the same answer, because 220 − 40 is also 180.

Limits and tips

• Estimates only. Neither method replaces a lab test.
• Cooper constants not yet verified. See above.
• Who was tested. Both studies used men. The heart-rate ratio study used well-trained men only.
• Measure resting heart rate properly: in the morning, lying still, before coffee.
• Health first. A 12-minute all-out run is hard. If you have a heart condition, symptoms on exertion, or have not exercised for a long time, talk to a doctor before testing.