Determining Your BMI With the English System
If you're using the English system, the BMI formula is:
Weight in pounds (lbs) divided by height in inches (in) squared and multiplied by a conversion factor of 703 (weight (lbs) / [height (in)2] x 703).
Therefore, to calculate BMI, take the weight (lbs) and divide it by height (in). Take the result of that calculation and divide it by height again. Then, multiply that number by 703. Round to the second decimal place.
An example of calculating body mass index using the BMI formula: Weight = 150 lbs, Height = 5'5" (65 inches)
BMI Calculation: [150 ÷ (65)2] x 703 = 24.96
(In place of using the formula to measure body mass index, you can use the BMI Calculator or the BMI Chart to get the same results.)