# How to Calculate Your BMI

​​​​​Your body mass index (BMI) is a number based on your weight in relation to your height. It's ​a good measure of body fat and is helpful in screening for weight issues that may cause health problems.

For adults age 20 and over, BMI is determined using the same formula for men and women.​

The calculation is slightly different for adolescents and adults. To determine the BMI for anyone under 20, use the BMI calculator provided by the Centers for Disease Control and Prevention. ​

Divide your weight in pounds by your height in inches squared, then multiply that ​number by 703.

Weight in Pounds ÷ (Height in Inches Squared) x 703 = BMI

​For example, someone who is 160 pounds and 5’ 8” (68 inches tall) would use this formula:

160 ÷ (68 x 68) x 703 = 23.4

​​​This person would first calculate their height in inches squared by multiplying 68 by 68, which equals 4,624. Next, he would divide 160 by 4,624, which equals 0.0346. He would finally multiply 0.346 by 703 for a B​MI of 23.4, which would fall in the normal range.