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 and underweight. BMI is calculated by dividing weight in kilograms by the square of height in meters.
BMI is a useful tool for assessing weight-related health risks, but it is important to note that it is not a perfect measure. BMI does not take into account muscle mass or body composition, so it can overestimate body fat in athletes and underestimate body fat in people who are overweight but have a lot of muscle.