body-mass index (BMI)

Measure of fatness or thinness of an adult person, computed by dividing his or her bodyweight (W) in kilograms by the square of the height (H) in meters: BMI = W ÷ H2. For imperial units (weight in pounds and height in inches) the formula is: BMI = 703.07 x W ÷ H2. In the US, a BMI of 19 or less is termed as underweight, 20 to 24 as average, 25 to 29 as overweight, and 30 or more as obese.