About
A free fitness age calculator from Catalyst Performance, a longevity-focused personal training studio in the Singapore CBD. Enter your age, sex and resting heart rate, and it returns your fitness age: the age at which your cardiorespiratory fitness would be average. If that number is higher than your real age, your heart and lungs are ageing faster than the calendar. It is the most shareable of our eleven calculators because it turns an abstract measure into one number you immediately understand. The maths is deterministic and runs entirely in your browser against published norm tables, with no account, no email capture and no server call, so nothing you enter is stored. The reference tables and their sources are published on the page, and where a figure is an estimate it says so and points to the measured version instead. Companion calculators cover VO2 max percentile, grip strength against sarcopenia thresholds, waist-to-height ratio, the sitting-rising test, GLP-1 muscle loss, fat loss, running pace, heart rate zones, protein intake and body fat percentage. All eleven are free to embed on any other website.