Body mass index (BMI) is a measure of body fat based on height and weight that applies to adult men and women.
BMI was developed in the 19th century by Adolphe Quetelet, a Belgian mathematician, astronomer, and statistician, as a way to classify obesity. BMI is calculated by taking a person’s weight in kilograms and dividing it by the square of their height in meters. The resulting number is then used to categorize the person as underweight, normal weight, overweight, or obese.