FFMI Calculator
Calculate your Fat-Free Mass Index, muscle ranking, and get a personalized 3-month fitness roadmap.
Fill in your details and click Calculate FFMI to see your personalized results and roadmap.
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Understanding FFMI
What is FFMI?
Fat-Free Mass Index measures your lean muscle relative to height — far more meaningful for athletes than standard BMI.
The Formula
FFMI = LBM ÷ Height(m)². LBM = Weight × (1 − BF% / 100). Normalized FFMI adds a height correction factor.
Natural Limit
Research suggests ~25 normalized FFMI as the ceiling for most drug-free men. Women's ceiling is approximately 21.
How to Improve
Progressive overload training, 1.6–2.2g protein per kg, adequate sleep, and consistent long-term effort drive FFMI gains.
Frequently Asked Questions
Find answers to common questions about Fat-Free Mass Index (FFMI) and body composition.