Fitness Age Calculator

Fitness age is the age at which your cardiorespiratory fitness, measured as VO2 max, equals the population average for your sex. If your fitness age is lower than your real age, your aerobic fitness is above average. If it is higher, you are below average for your years. The idea comes from research at the Norwegian University of Science and Technology (NTNU).

You enter your sex, age, and a measured VO2 max or an estimate from a validated exercise test. The calculator matches that value to sex-specific average VO2 max reference values and interpolates the age at which the average matches your result. That matched age is your fitness age.

This calculator does not make a non-exercise estimate from waist size, resting heart rate, or activity. Use a measured VO2 max or an estimate from a validated exercise test before entering a value.

Waist size and resting heart rate can be useful health measures, but they do not enter this calculator. Its result is based on the VO2 max value you provide, your age, and the selected sex-specific reference values.

A lower fitness age requires a higher VO2 max. Regular aerobic training can improve VO2 max, but the size and timing of any change depend on your starting fitness, training, recovery, and health. Use repeat measurements from a comparable test to track change.

No. This calculator is for education and general fitness tracking only and is not a substitute for professional medical advice, diagnosis or a supervised exercise test. Talk to a doctor before starting a new training program, especially if you have a heart condition, are over 45, or have other health concerns.