FFMI Calculator
Calculate your Fat-Free Mass Index — a measure of muscularity relative to height. See how you compare to natural limits based on peer-reviewed research.
FFMI
22.2
Fat-Free Mass Index (FFMI)
22.2
Normalized FFMI (height-adjusted)
22.5
Adjusted to 180cm reference height for fair comparison
Very well-developed musculature. Years of dedicated training.
FFMI scale (male)
Lean mass
68 kg
85.0%
Fat mass
12 kg
15.0%
Body composition
FFMI reference ranges (male)
What is FFMI? Fat-Free Mass Index measures how much muscle you carry relative to your height — like BMI but for lean tissue only. It's calculated as lean mass (kg) divided by height (m) squared. An FFMI above 25 in men (21 in women) is considered beyond what's achievable naturally by most people, based on research by Kouri et al. (1995).
Sources: Kouri et al. (1995) "Fat-free mass index in users and nonusers of anabolic-androgenic steroids", Clinical Journal of Sport Medicine 5(4):223–228; VanItallie et al. (1990) "Height-normalized indices of the body's fat-free mass and fat mass", American Journal of Clinical Nutrition 52(6):953–959. Normalized FFMI uses the correction factor FFMI + 6.3 × (1.8 − height in metres).