Body Mass Index Calculator Enter English or Metric Units Your Height: ft - in m Your Weight: lb kg Your Body Mass Index:   Interpretation The BMI is intended to be a simple measure of obesity. According to the Centers for Disease Control and Prevention, If your BMI is... You are... Under 18.5 Underweight Between 18.5 and 24.9 Normal Between 25 and 29.9 Overweight 30 and Over Obese   Limitations The Body Mass Index is defined as BMI = weight / height2 where weight is in kilograms and height is in meters. The obvious limitation of the BMI formula is that it doesn't distinguish between fat weight and (healthier) muscle weight. Bodybuilders and other athletes can easily have a BMI in the "obese" range and in fact be extremely lean.   Finding Ideal Weight You can also run the formula backwards: given your height and desired BMI (defaulted here to a mid-range "normal" value of 22), you can find your ideal weight: Enter English or Metric Units Your Height: ft - in m Your Ideal Body Mass Index: Your Ideal Weight: lb kg The same limitations still apply: the BMI formula can only give an approximate target weight for typical people.   home  |  features  |  diversions  |  glossary  |  calculator  |  about us  |  books