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FFMI Calculator
Fat Free Mass Index Calculator

Enter your measurements to calculate your Fat Free Mass Index (FFMI)

Unit System
Metric
Imperial
Male
About Fat Free Mass Index (FFMI)

Fat Free Mass Index (FFMI) is a measure that evaluates muscle mass relative to height, providing insights into body composition beyond what traditional BMI can offer. Unlike BMI, which doesn't distinguish between muscle and fat, FFMI focuses specifically on lean body mass.

The Normalized FFMI adjusts for height differences, making comparisons more accurate across individuals of different statures. This metric is particularly valuable for athletes, bodybuilders, and fitness enthusiasts who want to track muscle development over time.

How FFMI is Calculated:

1. Fat-Free Mass = Weight × (1 - Body Fat% ÷ 100)
2. FFMI = Fat-Free Mass ÷ Height²
3. Normalized FFMI = FFMI + 6.1 × (1.8 - Height in meters)
Note: Calculations use metric units internally (kg, meters). Imperial inputs are converted automatically.

FFMI Categories:

Men
< 16:Below Average
16-17:Average
18-20:Above Average
21-23:Excellent
24-25:Superior
> 25:Elite
Women
< 14:Below Average
14-15:Average
16-17:Above Average
18-20:Excellent
21-22:Superior
> 22:Elite

Important Notes: FFMI values above 25 for men and 22 for women are considered at the upper limit of natural genetic potential. Higher values may indicate exceptional genetics, enhanced training, or other factors.

Safety Information

This FFMI calculator is for informational and educational purposes only. Results should not replace professional medical advice, diagnosis, or treatment. Always consult with qualified healthcare professionals for personalized health assessments.

Accuracy Requirements

FFMI calculations require accurate body fat percentage measurements. Consider using DEXA scans, BodPod, or other reliable methods for the most accurate results. Bioelectric impedance and visual estimates may provide less accurate FFMI calculations.