Know Your BMI

A simple measurement can help detect your health risks.

Body Mass Index − BMI− estimates body fat based on height and weight. Underwater weighing gives a more exact measure of body fat, but is costly and not practical. BMI is used as a screening tool to place people in categories of underweight, normal weight, overweight, or obese.


What’s your number?

Childhood Obesity

To find your BMI, multiply your weight in pounds by 703.

Divide this number by your height in inches squared.


Example: Weight = 150 lbs; Height = 5’5” (65”)

Calculation: [(150 x 703) ÷ (65²)] = 24.96


If you’d rather not do the math, use the online calculator  from the National Heart, Lung, and Blood Institute at


How to Survive a Dieting Setback

Below 18.5 - Underweight

18.5 – 24.9 - Normal

25.0 – 29.9 - Overweight

30.0 and above Obese

Body Mass Index (BMI) table.

A BMI above the normal weight range is less healthy for most people. It may be fine if you have lots of muscle and little fat. In general, though, if your BMI is above the normal range, you are at an increased risk for many diseases and health conditions. These include:

•  Breathing problems

•  Gallbladder disease

•  High blood cholesterol

•  High blood pressure

•  Type 2 diabetes

•  Heart disease

•  Osteoarthritis

•  Some cancers, such as ones   of the breast, colon, kidney,  and pancreas

•  Stroke

The higher the BMI, the higher the risk for these problems.

Other factors to consider

Bodies vary. BMI does not take body fat percentage into account. For people who are very muscular, their BMI may overestimate body fat. BMI may underestimate body fat in older persons or those losing muscle. People over age 65 should check with their doctors for their  recommended BMI.

Action Step

Discuss your BMI with your doctor.  Ask about your personal risk of weight-related chronic diseases. Together, make an action plan to reduce your risks.

This website is not meant to substitute for expert medical advice or treatment. Follow your doctor’s or health care provider’s advice if it differs from what is given in this guide.


The American Institute for Preventive Medicine (AIPM) is not responsible for the availability or content of external sites, nor does AIPM endorse them. Also, it is the responsibility of the user to examine the copyright and licensing restrictions of external pages and to secure all necessary permission.


The content on this website is proprietary. You may not modify, copy, reproduce, republish, upload, post, transmit, or distribute, in any manner, the material on the website without the written permission of AIPM.