FFMI Calculator

Calculate your Fat-Free Mass Index.

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Estimate or use calipers/DEXA scan

FFMI = Lean Mass (kg) / Height^2 (m^2); Normalized FFMI = FFMI + 6.1 * (1.8 - Height in m)
Example: 180 lbs at 5ft 10in with 15% body fat = FFMI of 22.1 (above average fitness, naturally attainable). 25+ suggests enhanced physique

What is FFMI?

Fat-Free Mass Index (FFMI) measures lean body mass relative to height. It's like BMI but accounts for muscle mass, making it useful for athletes and bodybuilders.

What is a good FFMI score?

Average men: 18-20, Athletic: 20-22, Advanced lifters: 22-24, Natural genetic limit: ~25-26. Women typically score 3-4 points lower.

What is the natural limit for FFMI?

Research suggests 25-26 is the natural limit for most men. FFMI scores above 26 may indicate steroid use, though genetic outliers exist.