FFMI Calculator
Measure your true muscularity with the normalized FFMI. Based on Kouri 1995, with a natural vs. enhanced scale.
📊 Interpretation by FFMI value
The same FFMI reads differently depending on sex and on where it falls on the scale. Here is what each whole value from 16 to 25 means in practice, the room for growth it leaves, and the questions that come up most about it.
📐 How it is calculated
🧪 Cited studies
- Kouri, E. M. et al. (1995) — Fat-free mass index in users and nonusers of anabolic-androgenic steroids, Clin J Sport Med: introduces the normalized FFMI and the ~25 natural limit.
- Hodgdon, J. A. & Beckett, M. B. (1984) — the U.S. Navy method for estimating body fat % from circumferences.
- Casey Butt (2008) — Your Muscular Potential: fat-free mass ceiling based on frame size (wrist, ankle).
📋 Worked example
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