FFMI Calculator
Body CompositionCalculate your Fat-Free Mass Index to assess muscularity
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FFMI Calculator
Fat-Free Mass Index - Measure your muscularity level
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FFMI (Fat-Free Mass Index) measures how much lean mass you carry relative to your height. It's a better indicator of muscularity than BMI because it accounts for body fat percentage. The formula adjusts for height to allow fair comparisons.
The adjusted FFMI normalizes scores to a height of 1.8m (5'11"). This allows better comparison between people of different heights. The formula is: Adjusted FFMI = FFMI + 6.1 × (1.8 - height in meters)
FFMI is just one metric and doesn't account for bone structure, muscle insertions, or genetic variations. The "natural limit" is debated and varies individually. Focus on your own progress rather than comparing to theoretical maximums.
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Fat-Free Mass Index
FFMI measures muscularity independent of body fat.