Body mass index (BMI) is a measure of body fat based on height and weight. It is used to classify obesity and overweight, and to track changes in body weight over time. BMI is calculated by dividing weight in kilograms by height in meters squared. For example, a person who weighs 80 kilograms and is 1.8 meters tall would have a BMI of 80 / (1.8 x 1.8) = 25.
BMI is used by healthcare professionals to assess a person’s weight status. It is also used by researchers to study the relationship between obesity and health risks. BMI is a simple and inexpensive way to screen for obesity and overweight. It can be used by adults and children.