What is Body Mass Index (BMI)? How Can it be Calculated?

Body Mass Index (BMI) is a widely used statistic around the world. It is a popular choice among physicians, people who are at a risk of obesity or diabetes, as well as those who are just generally health conscious.

In simple terms, Body Mass Index (BMI) is a calculation that correlates your weight and height for determining body fat. It is a reasonable means of determining whether a person is underweight, normal, or overweight. However, the thing to remember is that BMI is not a direct measure of body fat. It simply correlates to direct measures of body fat. It has been used by doctors since the 1840’s to determine the general health of individuals. It is inexpensive and can be easily performed, hence its popular use.

What is the Basic Use of Body Mass Index (BMI)?

BMI is used essentially as a means of screening individuals with weight issues. But, it is in no way a diagnostic tool. A person having a high BMI can only be classified as obese or being at a risk of other ailments after other conclusive tests. These tests may include family history, lifestyle analysis, etc.

How to Calculate Body Mass Index (BMI)?

BMI can be calculated using two methods, namely the metric and imperial systems.

Metric System

For this method, the person’s weight (in kilograms) is divided by their height (in meters squared).

For example:

BMI = Weight (kg)    =       90kg      = 24.93.             [Height (m)]2           (1.9)2

Imperial System

In this method, the person’s weight (in pounds) is first multiplied by 703, and is then divided by their height (in inches squared).

For example:

BMI= Weight (lbs) x 703   =    190 x 703   = 25.76.           [Height (inches)]2                  (72)2

How is BMI Interpreted?

These are the general definitions of BMI which apply to most adults, as recommended by the World Health Organization:

BMI 40 = Morbidly obese

BMI in case of children is interpreted differently. Be sure to consult a doctor if your child has weight issues.

What Does Being ‘Underweight’ or ‘Overweight’ Mean?  Being both underweight and overweight can have their own adverse complications. Underweight individuals may be prone to diseases such as osteoporosis, absence of menses, iron-deficiency anemia etc. Being overweight may lead to heart conditions, diabetes, kidney disease, and even some types of cancer. Taking the necessary precautions is the key to remaining healthy.

How Accurate is BMI?

Healthcare professionals cannot rely solely on BMI. At similar values of BMI, women have more body fat than men. Same applies for older people and young adults. Furthermore, athletes have higher BMI’s because of muscularity, and BMI also varies among ethnic groups. Being an effective tool, it should not be used exclusively for predicting health issues.