How to Calcuate Your BMI

Body Mass Index is a measure of body fat that is calculated using height and weight. The National Institutes of Health (NIH) first announced the guidelines for calculating BMI in adults age 20 and older in 1998. The new guidelines replaced the charts that insurance companies had created and used to determine healthy weight. According to current NIH guidelines, a healthy BMI number falls between 18.5 and 24.9. A BMI under 18.5 is considered to be underweight, and a BMI over 24.9 is considered to be overweight. A BMI of 30 or more is considered obese.

Instructions

• 1

  Determine your weight in pounds and your height in inches.

• 2

  Square your height. For example, 75 inches multiplied by 75 inches.

• 3

  Divide your weight by your height squared. For example, 140 (weight in pounds) divided by 5,625 (height in inches squared).

• 4

  Multiply that number by 703. The complete formula for calculating BMI is: weight in pounds divided by height squared times 703.

• 5

  Use a BMI chart to determine where your final number falls (see Resources).