Fat Free Mass Index (FFMI) Calculator
Excessive fat in the body is harmful. There is a general tendency among people about keeping track of their weight without giving importance to the amount of fat content in their body. The irony which can arise here is that a person with less body weight vis-a- vis height can have a greater relative fat content and vice-versa. Therefore maintaining balanced body fat levels is essential and associated with a longer, disease-free life
Your result is classfied as
|Total body fat|
What is the fat free mass index?
Fat free mass index as the name suggests indicates the proportion of body weight which is free from fat. Therefore it provides us the muscle mass a person carries in correlation to their weight and height.
A major criticism of BMI is that a person with high fat content and a person with high muscle content can have the same BMI with their height and weight being the same. There will be major differences between the two people when it comes to their health, energy, looks, stamina, immunity, risk to various diseases like cardio- vascular and diabetes. Therefore BMI, does not bring into light the various weakness a person can have in spite of having their weight within limits. This criticism of BMI is addressed by FFMI.
FFMI helps track fat loss progress as well as muscle building processes. It is often used by athletes, fitness enthusiasts and body builders.
Thenormal FFMI for males is around 19 and anything above 25 is rare.
Along with Body height and Body weight, the FFMI uses Body Fat percentage as inputs.
The Importance of Healthy Fat-Free Mass (FFM)
Having Fat free mass helps in leading a healthy lifestyle and keeps the risks of high blood pressure, type 2 diabetes, heart disease, and even obesity-related depression away.
The opposite of FFMI is fat mass index(FMI), which accounts for adipose tissue, otherwise known as body fat. Fat free mass is a phrase used to describe all of the tissues in your body that are not adipose (fat) tissue.
FAT FREE BODY MASS
Internal organs such as heart, brain, and liver
Cardiac muscle, smooth muscle, and skeletal muscle. Skeletal muscles contract to produce movement in your body and perform other essential duties
Protect the body and provides structure
Tendons and ligaments that connect the body's bones and muscles.
Approximately 50-75 percent of body is water. Water is free from fat and can be considered fat free mass.
To reap the benefits of weight loss, one should try to decrease the fat mass and improve fat free mass like muscle and bone..
The body fat percentage is much higher in most of the people which is the reason for obesity
Our body needs just the right amount of fat to keep it healthy. Athletes have low body fat which helps them perform at their peak. Fitness of athletes is the result of reduction in body fat percentage.
The American Council on Exercise (ACE) published the following body fat chart according to different fitness levels
Men % Body fat
Women % Body fat
25 and higher
32 and higher
How do you calculate fat free mass?
The FFMI calculator uses currently approved mathematical formulas for computing the fat-free mass, FFMI as well as Normalized FFMI . The latter is dedicated for taller athletes who are bigger overall.
Body fat calculation is done by the simple equation: body fat = weight [kg] * (body fat [%] / 100). It is expressed in kilogram units [kg].
Fat free mass is calculated using the following method: fat free mass = weight [kg] * (1 - (body fat [%]/ 100)) expressed in kilogram units [kg].
FFMI vs normalized FFMI Calculation
FFMI calculation: FFMI = fat free mass [kg]/ (height [m])². Expressed in kilograms per square meter [kg/m²].
For Normalized FFMI the equation is normalized FFMI = FFMI [kg/m²] + 6.1 * (1.8 - height [m]). The same unit as in FFMI [kg/m²].
Fat-Free Mass Index calculator allows you to change the units which are displayed. You can switch between cm, m, kg, lb, etc., accordingly to your needs and preferences.
Vitruvian physique FFMI
Reducing the fat content and developing the muscles would not only increase FFMI but also would help in building a Vitruvian physique as portrayed in Leonardo da Vinci's drawing titled the Vitruvian Man which depicts the ideal proportions of man.
What is your fat free bodyweight?
Fat-free body weight, also known as lean body weight, refers to all of your body components except fat. It includes your body's water, bone, organs and muscle content.
Fat free body weight chart
Men % fat free body weight
Women % fat free body weight
75 and less
68 and less
Why is it Different for Men and Women in FFMI?
The difference in body composition for men and women results in difference in FFMI. Men biologically possess less body fat, more muscle mass, and greater bone density compared to women. Women, on the other hand, naturally have more body fat to maintain their menstrual cycle and support childbirth.
Females tend to develop adipose tissue, which is loose connective tissue composed of fat around their hips and thighs. Men, on the other hand, commonly accumulate adipose fat around the trunk of their body and abdomen.
The table below shows men and women's FFMI scores with their corresponding percentile. Basically, the higher your percentile, the leaner body mass you have.
FFMI by percentile
The below table shows the FFMI and body fat percentage for men with different body types(including FFMI athletes)
FFMI Ranges for Men
Body fat percent
Typical average guy
Athlete / regular gym user
Advanced gym freak
Elite strength athlete (bodybuilders, etc.)
From the above table for instance, a person with 21.6 FFMI would most probably be an athlete or a regular gym user.
The below table shows the FFMI and body fat percent ranges for women with different body types(including FFMI athletes)
FFMI Ranges for Women
Body fat percent
Typical average woman
Athlete / regular gym user
Advanced gym freak
Elite strength athletes (bodybuilders, etc.)
Is FFMI Different from BMI?
FFMI is different from BMI as FFMI is a measure a fat free mass which provides the necessary fitness, agility and a disease risk free lifestyle. BMI though checks the body weight relative to height misses out on the healthy component of the weight. BMI does not distinguish fat from muscle when there is a huge difference between them.
Lean athletes can have higher BMI despite not being obese or overweight. Also two men may have the same height and weight. But one person would be muscular with chiseled abs and the other would be plain with a bulging midsection.The BMI would be the same, but the physical difference is striking.
BMI automatically assumes individuals gain weight from fat. Hence, it becomes a negative health indicator. Therefore, FFMI is a better measuring tool for lean and active people.
What about High Muscle Mass in Sumo Wrestlers FFMI?
Sumo wrestlers have an excessively high BMI score because of their heavy body weight which according to the BMI scale classifies them as obese. However, they have a remarkable muscle development and therefore they have an excessive fat free mass. Hence their FFMI score is exceptionally high.
The extremely large body size of sumo wrestlers is mainly due to the nature of competition. In sumo wrestling, the most important factor for winning is the momentum produced from the product of the wrestler’s body mass and the velocity of his charge.
Therefore, increasing both mass and velocity through increased fat free mass is more advantageous than increasing mass at the expense of velocity. Hence Sumo wrestlers have a great amount of fat free mass that has been described as the upper limit for humans.
Frequently Asked Questions
Is FFM the same as lean body mass?
No, despite the fact that FFM and LBM are often used interchangeably, they are not the same. Lean body mass consists of fat, which is used as a source of energy for metabolism-related functions and other processes. Fat-free mass, on the other hand, does not include any fat.
How does age affect the Fat Free Mass Index?
Aging has numerous effects on the Fat Free Mass Index (FFMI). First off, muscle mass tends to decline with age, which can lower FFMI. Second, FFMI may also vary as a result of changes in body composition with age. Third, age-related hormonal changes can also have an impact on FFMI.