Body mass index (BMI) is a measure of body fat based on height and weight. It is used to screen for weight-related health problems such as obesity, underweight, and eating disorders.
BMI is calculated by dividing weight in kilograms (kg) by the square of height in meters (m2). For example, a person who is 1.7 meters tall and weighs 70 kilograms has a BMI of 24.1.