Body Mass Index
Sometimes refered to as Height / Weight Ratio, the Body Mass Index (BMI) is a statistical measurement which compares a person's weight relative to their height. Though it does not actually measure the percentage of body fat, it is a useful tool to estimate a healthy body weight based on how tall a person is.
Due to its ease of measurement - requiring no specialised equipment - and its ease of calculation, it is the most widely used diagnostic tool to identify weight problems within a population.
By itself, BMI is a useful indicate of whether a person is overweight. However, It is possible for a trained athlete with very low body fat to be incorrectly classified overweight or obese, when in fact they are muscular.
