VO2 max from resting heart rate calculator
A quick cardio fitness estimate that needs only two numbers most sports watches already show.
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Processing and privacy: The result is calculated inside your browser and your data is not sent to any server.
How to use it
- Enter max heart rate and resting heart rate.
- The result appears straight away and updates as you edit.
- Copy the result, or copy a link that keeps the same values to share it.
How it is calculated
Uth et al. (2004): VO2 max = 15.3 × (max heart rate ÷ resting heart rate), in mL per kg per minute.
Example
Inputs: Max heart rate = 185 bpm, Resting heart rate = 55 bpm. Result: Estimated VO2 max: 51.5 mL/kg/min; Max to resting heart rate ratio: 3.36.
Limits and caveats
- It was developed on trained men aged 21 to 51 and may be less accurate for others.
- If you estimate max heart rate from age instead of measuring it, accuracy drops.
Questions about this tool
How can VO2 max be estimated without exercise?
A fitter heart beats slower at rest while max heart rate stays similar, so the ratio between them reflects aerobic fitness.
Where do I get my max heart rate?
The most reliable source is the highest reading your watch recorded in an all-out effort, or use a max heart rate calculator.
Is this more accurate than the Cooper test?
Usually not, since exercise tests measure performance directly. This method is useful for tracking change over time.