BMI, short for Body Mass Index, is a measure of body fat based on height and weight. It is calculated by dividing weight in kilograms (kg) by the square of height in meters (m). For example, a person who weighs 70 kg and is 1.75 m tall would have a BMI of 23.1.
BMI is used to assess the level of body fat and to identify people who are overweight or obese. It is also used to track changes in body weight over time. The development of BMI is credited to Adolphe Quetelet, a Belgian mathematician and statistician, in the 19th century.