FFMI Calculator: Calculate Your Fat-Free Body Mass Index (FFMI)

Calculating your fat free mass index (FFMI) is a great way to measure the amount of muscle mass relative to height. This index is commonly used by bodybuilders to compare themselves to others and track progress over time.

FFMI calculator

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Fill the calculator form and click on Calculate button to get result here
Fat free mass 0
Body fat 0
FFMI ? 0
Normalized FFMI ? 0
FFMI Interpretation: 0

Fat-Free Mass Index (FFMI) is a measurement that helps to determine the amount of muscle mass an individual has relative to their height and body fat percentage. It is considered a more accurate method of measuring muscle mass compared to traditional body weight or body mass index (BMI) calculations.

Understanding and tracking your FFMI can be a useful tool in setting and achieving fitness goals. In this article, we will provide an explanation of how to use an FFMI calculator and its importance in measuring muscle mass.

How to use calculator

To estimate your FFMI, follow the steps:

  • Enter your height
  • Enter your weight
  • Enter your body fat percentage
  • Click the “Calculate” button to get the results.

Understanding Fat-Free Mass

Fat-free mass refers to the weight of your body that is not made up of fat. This includes muscle, bone, water, and other non-fat tissue. To calculate your fat-free mass, you need to know your body weight and body fat percentage. The higher your fat-free mass, the more muscle mass you have. Having a high fat-free mass is important for maintaining good health and for achieving a lean, fit physique.

FFMI formula

  • Total Body Fat = Weight * (body fat [%] / 100)
  • Lean Weight = Weight * (1 – (body fat [%] / 100)
  • FFMI = (Lean Weight / 2.2) / ((Feet * 12.0 + Inches) * 0.0254)2
  • Adjusted FFMI = FFMI + ( 6.3 * (1.8 – (Feet * 12.0 + Inches) * 0.0254))

Understanding Your Results

Your FFMI score will fall into one of three categories: low, average, or high. A score of less than 18 is considered low, 18-25 is considered average, and above 25 is considered high. A high score indicates a high amount of muscle mass relative to body fat. Use your FFMI score to set specific, measurable fitness goals and track your progress over time. Adjust your training and nutrition as needed to meet your goals.

FFMI for men

FFMI Body fat Description
17-18 10-18% Skinny man
18-20 20-27% Average man
19-21 25-40% Fat man
20-21 10-18% Athlete / Intermediate gym user
22-23 6-12% Advanced gym user
24-25 8-20% Bodybuilder / Powerlifter / Weightlifter

FFMI for women

FFMI Body fat Description
14-15 20-25% Skinny women
14-17 22-35% Average women
15-18 30-45% Fat women
16-17 18-25% Athlete / Intermediate gym user
18-20 15-22% Advanced gym user
19-21 15-30% Bodybuilder / Powerlifter / Weightlifter


Measuring muscle mass is important for setting and achieving fitness goals, and the FFMI calculator is an accurate tool for doing so. By understanding fat-free mass, how to use an FFMI calculator and interpreting the results, you can track your progress and make adjustments to your training and nutrition to reach your desired muscle mass.

Remember to regularly measure your body fat percentage and use the FFMI calculator to track your progress. Additionally, you can consult other resources for more information and further reading.

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