I got this in an email today so not sure how accurate it is.

(HealthDay News) -- Body-mass index (BMI) is a good indicator of
whether you are at a healthy weight.

The U.S. National Library of Medicine says BMI is calculated by
multiplying your weight in pounds by 703, and dividing that number
by your height in inches. Then divide the result again by your
height in inches.

The agency offers the following ranges for interpreting BMI:

* A score below 18.5 indicates being underweight.
* Between 18.5 and 24.9 means a healthy body weight.
* Between 25 and 29.9 means you are overweight.
* Between 30 and 39.9 indicates obesity.
* A score of 40 or higher indicates morbid obesity.