FFMI Calculator – Powerful Fat-Free Mass Index & Normalized FFMI Tool

FFMI calculator helps gym-goers, bodybuilders, and fitness-focused users estimate fat-free mass index and normalized FFMI from body weight, height, and body fat percentage. It is designed for people who want more context than BMI by focusing on lean mass rather than total body size alone. Users enter weight, body fat percentage, and height, then receive FFMI-style results that are easier to compare across different body sizes.

FFMI Calculator Ajax

Estimate your Fat-Free Mass Index (FFMI) and normalized FFMI (to 1.80 m). Results update instantly.

⚖️ Weight

Tip: Use your current body weight. Units convert automatically on change.

🧮 Body fat (%)

Tooltip: Estimated proportion of body fat. Accepts 0–70%.

📏 Height

Tooltip: Enter either in cm, or in feet and inches. Switching modes converts values.

🧰 Actions

Reload clears inputs & results.

Live Results

Fat-free mass

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FFMI

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Normalized FFMI (to 1.80 m)

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Step-by-step derivation

Enter values to see the algebra with your numbers.

Quick summary

Results will appear here when you add your weight, body fat, and height.

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