What is BMI?

BMI is an inexpensive and easy-to-perform method of screening for weight categories that may lead to health problems.BMI is a fairly reliable indicator of body fatness for most people.It is calculated from your height and weight. The formula used is: weight (lb) / [height (in)]2 x 703. Often, your BMI score is determined by taking your weight and height and plotting them on a chart or by using a web-based BMI calculator.

You can calculate your BMI here:

The BMI score classifies individuals into the following categories:


Underweight Below 18.5
Normal 18.5–24.9
Overweight 25.0–29.9
Obesity 30.0 and Above

Why is it important?

The BMI ranges are based on the relationship between body weight and disease and death. Overweight and obese individuals are at increased risk for many diseases and health conditions, including the following:  heart disease, high blood pressure, stroke, type 2 diabetes, gallstones, breathing problems, osteoarthritis, and certain cancers.

What are the limitations of BMI?

Although BMI can be used for most men and women, it does have some limits:

  • It may overestimate body fat in athletes and others who have a muscular build.
  • It may underestimate body fat in older persons and others who have lost muscle.

Where can I get more information?