How To Calculate Body Mass Index


Health is the biggest asset for everyone. You can take care of yourself by this simple calculation. Here you will get to know how BMI reveals obese condition.

How To Calculate Body Mass Index

Body Mass Index acts as a calculator for human body fat. Human body fat is calculated by an individual’s weight and height. Here individual’s body weight divided by the square of his or her height. The formula is globally used in medicine field to produce a unit of measure of kg/m2. It does not require any standard tables. It is also called Quetlet index.


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In SI units

BMI = weight (kg)/ height2 (m)
In US Customary units
BMI= mass (lb) x 703 / (height (in))2
BMI= mass (lb) x 4.88 / (height ft)) 2
BMI= mass (st) x 9840 / (height (in))2

BMI Related To Health Issues- Obesity

Do you know that obesity is a growing global concern? Yes, it is one of the major health complications. According to WHO, obesity is defined as the abnormal or excessive fat accumulation that may impair health. Accumulation of excessive amount of adipose tissue in the body leading to undesirable weight gain is termed as obesity.

It is mainly due to positive energy intake. Excess food consumed is converted into fat and stored in the adipose tissues. In men, fat is predominantly distributed in upper part of the body (chest, shoulder). But for women it is different.

The fat is deposited in the lower part of the body (lower abdomen, buttocks, hips and thighs). If the body weight is 10% above ideal weight, the condition is termed as overweight and if it is 20% above ideal weight, it is referred as obesity.

How It Occurs?

It occurs due to excess accumulation of fat in our body. It leads to series of complications like apnoea, atherosclerosis, liver disorders, gastrointestinal complications, hyperlipidemia, etc. Both clinical and nutritional intervention is required to reduce the risk of obesity.

Etiology of Obesity

Hereditary cause, if both the parents are obese the child has 80% chance for obesity
Eating excess of fried foods and junk foods may lead to obesity. Physical inactivity is very common in those who lead a sedentary life. Obesity is more common among the low income groups as they consume more junk and cheap fatty foods.

How To Calculate Body Mass Index

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How To Assess Obesity?

Obesity can be assessed by the following procedures.

By Body weight

It is a common method used to determine the degree of obesity.
If there is 25 % body weight excess from normal leads to Mild Obesity
If there is 50 % body weight excess from normal leads to Moderate Obesity
If there is 75 % body weight excess from normal leads to Severe Obesity
If there is 100 % body weight excess from normal leads to Very Severe Obesity


Another common method used to determine the degree of obesity.
If BMI is >40 means Grade III
If BMI is 30 – 40 means Grade II
If BMI is 25 – 29.9 means Grade I
If BMI is <25 means not obese

By Waist Circumference

An inch tape is used measure the waist circumference. This is the most commonly used tool by clinicians to evaluate obesity. Men are termed as obese, if their waist circumference is greater than 40 inches (>102 cm) and for women it is greater than 35 inches (>88 cm).

By Waist To Hip Ratio

Waist measurement (in cm) / hip measurement (in cm)
Condition – For male >1.0 means Obese
For female >0.85 means Obese
Normal waist to hip ratio is 0.7
This simple calculation will change your lifestyle.  Be healthy!