Method
The calculator uses a simple heart-rate ratio estimate: VO2 max = 15.3 x maximum heart rate / resting heart rate.
Example
With a maximum heart rate of 185 and resting heart rate of 60, the estimate is 15.3 x 185 / 60 = about 47.2 ml/kg/min.
Common mistakes
Estimated maximum heart rate can be far from a person's measured maximum. Resting heart rate should be taken when rested, not after caffeine, stress or exercise.
Limitations
This is not a clinical exercise test. Use supervised testing when results affect training, health screening or occupational requirements.
References
- CDC: measuring physical activity intensity, accessed 2026-05-17.
Last reviewed: 2026-05-17