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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