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How to Interpret BMI

by Allan Robinson

About Allan Robinson

Allan Robinson has written numerous articles for various health and fitness sites. Robinson also has 15 years of experience as a software engineer and has extensive accreditation in software engineering. He holds a bachelor's degree with majors in biology and mathematics.


If you want to know whether you're at a healthy body weight, knowing how to calculate and interpret your body mass index (BMI) can come in handy. Used by physicians as a preliminary screening tool rather than a diagnosis, your BMI is convenient to calculate, because it only requires that you know your height and your weight. You can use a BMI reference chart to interpret the significance of your BMI once you calculate it.

Step 1

Stand on a scale and weight yourself. You'll need to divide your weight by 2.2 if you measured your weight in pounds. This will provide your weight in kilograms.

Step 2

Measure your height with the tape measure. You'll need to multiply your height by 0.0254 if you measured your height in inches. This will provide your weight in meters.

Step 3

Derive your BMI. Divide your weight in kilograms by your height squared in meters. This will provide your BMI in units of kilograms per square meter (kg/m^2.) You need to know your BMI in metric units because this is what most BMI references use.

Step 4

Consult the BMI chart to determine your results. A BMI below 19.1 for a female is classified as underweight. The normal range for a female BMI is 19.1 to 25.8. A female BMI that's between 25.8 and 27.3 is classified as marginally overweight, and a female BMI between 27.3 and 32.3 is classified as overweight. A BMI above 32.3 for females is classified as obese.

Items you will need

  • Scale
  • Tape Measure
  • Calculator
  • BMI chart

Photo Credits:

  • Jupiterimages/Stockbyte/Getty Images

This article reflects the views of the writer and does not necessarily reflect the views of Jillian Michaels or JillianMichaels.com.