Fat Free Mass Index Calculator

 
Gender
Weight
kilos
Height
meters
Body fat
%
Fat-free mass  =  68.4kilos
Body fat  =  21.6kilos
FFMI  =  18.947
Normalized FFMI  =  18.337
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Fat Free Mass Index Calculator

    Fat Free Mass Index (FFMI) Calculator uses body weight, height, and body fat to calculate the amount of muscle mass relative to input parameters. We can also adjust the FFMI reading from the above a 1.8 meter for men and 1.63 meter for women. FFMI calculator is useful as an indicator for the detection of malnourished individuals in specific subpopulations.

    The FFMI uses three inputs to provide a score of muscle mass. It is necessary to follow the next steps:
  • Enter the Body weight, measured in kilograms. The value must be positive in the range [0, 250];
  • Enter the Body height, measured in meters. The value must be positive in the range [0.3, 2.3];
  • Enter the Body fat, measured in percent units. This value must be positive in the range (0, 50);
  • Press the ”Calculate” button to make the computation;
Body Fat Formula:
The body fat can be calculated by the following formula
body fat = weight × body fat percentage 100

Fat Free Mass Formula:
Fat free mass is
fat free mass = weight × ( 1 − body fat percentage 100 )

Fat Free Mass Index Formula:
FFMI can be calculated by the following formula
FFMI = fat free mass height2

Normalized FFMI Formula (for men):
Normalized FFMI (for men) is
normalized FFMI = FFMI + 6.1 × (1.8 − height)

Normalized FFMI Formula (for women):
Normalized FFMI (for women) is
normalized FFMI = FFMI + 6.1 × (1.63 − height)

What is FFMI-Fat-Free Mass Index?

    Firstly, we should know our body fat parameter in percentage. If we don’t know it, we can use the body fat calculator to get this parameter.
    Fat-Free Mass Index, or shortly FFMI, finds the amount of muscle mass in relation to weight, height, and body fat. FFMI is part of the body indexes, and it is an excellent measure of mus- cularity. Although the FFMI is less used, it is more precise than BMI (Body Mass Index) which also provides information about a person’s condition and health. FFMI allows distinguishing between fat gain and muscle gain. If the mass of fat increases, then the FFMI index decrease, and if the mass of muscle increases, the FFMI index increases. For people, with more muscle mass than average, the FFMI calculator would be a very useful tool.
    On the other hand, the Normalized FFMI is intended for persons who are taller in height. The normalized FFMI formula adjusts the FFMI reading from the above a 1.8 meter for men and 1.63 meters for women. Normalized FFMI corrects FFMI by using linear regression. It is identical to the non-normalized FFMI value for a person who is taller than the mean value of the population.

How to calculate FFMI?

    FFMI is equivalent to free fat body mass in kilos divided by height in meters squared. The corresponding equation is
FFMI = fat free mass height2
It is expressed in kilograms per square meter. The average score for men is 19, and average score for women is about 15.
    To perform a proper calculation, we need to know body fat result in percentages. The body fat value estimates what percentage of our total body weight is body fat. The FFMI calculator uses mathematical formulas for computing the fat-free mass, FFMI as well as Normalized FFMI.
    For example, let us calculate FFMI for a man who has 1.9 meters, weighs 90 kilograms, and has 24% of body fat. Firstly, we calculate body fat
body fat = 90 × 24 100 = 21.6 kg
    The next step is to estimate fat free mass by using its formula, so
fat free mass = 90 × ( 1 − 24 100 ) = 68.4 kg
    Now, the FFMI and normalized FFMI (because the men is taller than the mean value, 1.8m) are given, respectively
FFMI = 68.4 1.92 = 18.84 kg m2
normalized FFMI = 18.84 + 6.1 × (1.8 − 1.9) = 18.23 kg m2
    The normalized FFMI is 18.23 kg/m2, it classifies our man to the average result, the message with the classification range is displayed automatically below the calculator.
    Fat-Free Mass Index calculator allows us to change the units which are displayed. We can switch between centimeters, meters, kilograms, pounds, etc., according to needs and preferences.

Fat-Free Mass table

    The following table indicates the classification of normalized FFMI indexes for men and women. It is very clear that the body composition of men and women is different. Men possess less body fat, more muscle mass, and greater bone density compared to women. Women, on the other hand, have more body fat to maintain their menstrual cycle and support childbirth.

Men
normalized FFMI Body Fat (%) Description
17 − 18 10-18 Skinny
18 - 20 20 - 27 Average
19 -21 25 - 40 Fat
20 - 21 10 - 18 Athlete/ Intermediate gym user
22 - 23 6 - 12 Advanced gym user
24 - 25 8 - 20 Bodybuilder/Weightlifter

Women
normalized FFMI Body Fat (%) Description
14 − 15 20-25 Skinny
14 - 17 22 - 35 Average
15 -18 30 - 45 Fat
16 - 17 18 - 25 Athlete/ Intermediate gym user
18 - 20 15 - 22 Advanced gym user
19 - 21 15 - 30 Bodybuilder/Weightlifter

    We can conclude that a normal average FFMI value for men is around 19 (and 16 for women), while a value above 25 (and 21 for women) indicates steroid usage.