The BMI is one way to determine whether or not an adult is overweight. BMI assesses height and weight; muscle mass is not a part of the equation.
BMI is calculated by dividing a person's weight (in kilograms) by his or her height (in meters, squared). BMI can also be calculated by multiplying weight (in pounds) by 705, then dividing by height (in inches) twice.
The chart below shows examples of body mass indexes. The figure at which your height corresponds with your weight is your body mass index. To find yours, consult the chart, or try our BMI Calculator.
A person with a BMI of 18.5 to 24.9 is considered to be at a healthy weight. A person with a BMI of 25-29.9 is considered to be overweight. A BMI over 30 is considered obese. A BMI of 40 or above indicates that a person is morbidly obese. This can increases a person's risk of death from any cause by 50% to 150%.