FFMI Calculator
Calculate your Fat-Free Mass Index to assess muscle mass and body composition
Calculate Your FFMI
Height in centimeters
Weight in kilograms
Body fat percentage (use our body fat calculator if unknown)
FFMI Results
FFMI Analysis
Example Calculation
Athletic Male Example
Height: 180 cm (5 feet 11 inches)
Weight: 85 kg (187 lbs)
Body Fat: 12%
Fat-free mass: 85 × (1 - 0.12) = 74.8 kg
FFMI: 74.8 ÷ (1.80)² = 23.1 kg/m²
Category: Superior (male)
Athletic Female Example
Height: 165 cm (5 feet 5 inches)
Weight: 60 kg (132 lbs)
Body Fat: 18%
Fat-free mass: 60 × (1 - 0.18) = 49.2 kg
FFMI: 49.2 ÷ (1.65)² = 18.1 kg/m²
Category: Excellent (female)
FFMI Categories (Males)
FFMI Categories (Females)
FFMI Tips
FFMI is more accurate than BMI for athletic individuals
Requires accurate body fat percentage measurement
Helps distinguish between fat gain and muscle gain
Normalized FFMI accounts for height differences
Understanding Fat-Free Mass Index (FFMI)
What is FFMI?
Fat-Free Mass Index (FFMI) is a measure that describes the amount of muscle mass relative to height and weight. Unlike BMI, which doesn't distinguish between muscle and fat, FFMI provides a more accurate assessment of body composition, especially for athletes and trained individuals.
Why is FFMI Better than BMI?
- •Distinguishes between muscle mass and fat mass
- •More accurate for athletic and muscular individuals
- •Helps track muscle gain vs fat gain
- •Can identify potential steroid use in competitive athletics
FFMI Formulas
Fat-free mass = Weight (kg) × (1 - Body fat % / 100)
FFMI = Fat-free mass (kg) / Height (m)²
Normalized FFMI = FFMI + 6.1 × (1.8 - Height in meters)
Important Notes
- !Requires accurate body fat percentage measurement
- !Different reference ranges for males and females
- !Normalized FFMI adjusts for height differences
- !High values may indicate steroid use in competitive contexts
Medical Disclaimer: FFMI is a research tool and should not replace professional medical advice. Always consult healthcare providers for health assessments.