Build Tool
FFMI Calculator
Fat-Free Mass Index — how much muscle you carry for your height, and how much room is left.
FFMI = lean mass ÷ height²; the normalised version adjusts everyone to the same reference frame (5 ft 11 in / 1.80 m). Most trained natural men land between 19 and 24. The result is only as honest as your body-fat input — underestimating body fat inflates FFMI fast.
General information for healthy adults — not medical advice. If you have a medical condition, are on medication, or anything feels off, talk to a doctor before acting on numbers from any calculator.
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