What this tool does
The Fitness Age Calculator turns your VO₂ max into a fitness age — the age at which your cardiorespiratory fitness would be average for your sex. It shows how many years younger or older that is than your real age, rates it from Excellent to Poor, and suggests ways to improve.
How it works
Population-average VO₂ max falls roughly linearly as people age. The tool inverts that line: given your VO₂ max, it solves for the age at which the average person would have that value, and reports it as your fitness age. The logic is a pure function, so the same inputs always produce the same result.
Important
This tool is for general information and motivation only — it is not medical advice and is based on population averages, not a clinical assessment. Consult a qualified healthcare professional before starting or changing an exercise programme.
Privacy
Everything runs locally in your browser. Your health inputs are never uploaded, logged, or stored.