Fat-Free Mass Index (FFMI) estimates muscularity relative to height by separating lean mass from fat mass.
Inputs
FFMI = Fat-free mass (kg) ÷ height² (m²). Body fat % is used to estimate fat-free mass.
Your reading
Your result
Rated using the FFMI bands for your selected age group.
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Very LowBelow AvgAverageAbove AvgHighSuperior
Time to goal
Estimates how long it may take to increase lean mass based on your training status and bodyweight.
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This treats the goal as lean mass gained. (Real-world scale weight may also change.)
These rates are population-level expectations and assume consistent training, nutrition, sleep, and recovery.
Actual results vary by genetics, program quality, starting point, and adherence.
