Body mass index (BMI) is a measure that uses height and weight to estimate body fat. It is calculated by dividing weight in kilograms by the square of height in meters. For example, a person who is 1.75 meters tall and weighs 70 kilograms has a BMI of 22.6.
BMI is a useful tool for screening for weight-related health problems. It is not a perfect measure, but it can help to identify people who are at risk for developing obesity, heart disease, stroke, type 2 diabetes, and some types of cancer. BMI was first developed in the 19th century by Adolphe Quetelet, a Belgian mathematician and statistician.