FFMI Calculator
Calculate unadjusted fat-free mass index from weight, height and a supplied body-fat percentage.
Formula
Fat-free kg = weight×(1−fat%/100); FFMI = fat-free kg / height m².
Weight: 176 lb · Height: 71 in · Fat-free mass ≈ (176 lb × 0.45359237 kg/lb)×(1-(20)÷100) · Unadjusted FFMI ≈ (63.8658057)÷(71 in × 0.0254 m/in)^2
How to use
- Enter weight and height.
- Enter a measured or estimated body-fat percentage.
- Read FFMI and fat-free kilograms.
Examples
- 80 kg, 200 cm, 20% fat: 64 kg fat-free mass; FFMI 16.00.
Frequently asked questions
Is FFMI a direct muscle measurement?
No. Fat-free mass also includes bone, organs and water, and depends on body-fat measurement accuracy.
Does a high FFMI prove steroid use?
No. This tool applies no doping verdict or universal cutoff and does not normalize to a reference height.
Does this replace medical advice?
For information only; it does not replace a doctor or individual assessment.
Sources
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