Body Mass Index (BMI) is a number calculated from a person’s weight and height. BMI provides a reliable indicator of body fatness for most people and is used to screen for weight categories that may lead to health problems.

References:

Welborn TA, Dhaliwal SS, & Bennett SA (2003). Waist–hip ratio is the dominant risk factor predicting cardiovascular death. The Medical Journal of Australia; 179 (11/12): 580-585. [link]
Centers for Disease Control and Prevention [link1, link2]

Instructions

Take circumference measurements in either centimeters or inches. Waist circumference is measured around the narrowest point between ribs and hips when viewed from the front after exhaling. Hip circumference is measured at the point where the buttocks is maximumally extended, when viewed from the side.

Enter information in left column; select appropriate gender and score and rating criteria. Age is not necessary for "Absolute" criteria. Click "Calculate". Evaluates adults (18 and older) risk of coronary artery disease and diabetes.