FFMI Calculator
Fat-Free Mass Index — assess your muscle mass relative to height
Enter Your Details
Enter your details
Weight, height, and body fat % needed
Related Calculators
References
- Kouri EM, et al. Arch Fam Med. 1995;4(9):783-785
- Heymsfield SB, et al. Am J Clin Nutr. 2016;103(5):1197-1203
- National Strength and Conditioning Association - Body Composition Guidelines
About Fat-Free Mass Index
How It Works
FFMI (Fat-Free Mass Index) adjusts your lean body mass for height, similar to how BMI adjusts total weight. It provides a more accurate assessment of muscularity by isolating muscle mass from body fat. The formula uses your weight, body fat percentage, and height to calculate lean mass relative to your frame size.
How to Interpret Results
Average FFMI for men is 18-20, for women 14-16. Competitive athletes typically score 20-22, and elite bodybuilders may reach 24-26. Scores above 25 in men (without performance-enhancing drugs) are exceptionally rare. FFMI below 16 in men or 13 in women may indicate low muscle mass or malnutrition.
Training Tips
To increase FFMI: focus on progressive overload in resistance training, consume adequate protein (1.6-2.2 g/kg body weight), maintain a slight caloric surplus for muscle gain, prioritize compound movements like squats and deadlifts, and ensure sufficient recovery between sessions.
Last reviewed: July 16, 2026
Medical Disclaimer: This calculator is for educational and informational purposes only. It is not a substitute for professional medical advice, diagnosis, or treatment. Always consult your physician or qualified health provider with any questions regarding your health.