Do You Weigh Too Much? Use Your BMI the Right Way to Find Out

There are many ways to determine your health. Some are completely valid, while others — like comparing yourself to Mark Wahlberg — are not. One of the most accessible and widely used tools to determine health is your Body Mass Index (BMI). The BMI is a tool that takes into account your height and weight to obtain a fairly accurate measure of body fat. Depending on your stats, you’ll fall into one of four categories: underweight, normal weight, overweight, or obese.

Why it works

Man measuring his BMI

Man measuring his BMI | iStock.com

It is one of the simplest and most effective ways to determine where you fit on the spectrum of physical health. All you have to do is plug your current height and weight into one of the many online calculators to determine where you fall on the index. It’s as unobtrusive and easy as it sounds.

While it doesn’t actually measure body fat — like underwater weighing and dual energy x-ray absorptiometry — studies have shown that in most cases an individual’s BMI results often match more direct measures of body fat. Furthermore, studies show that BMI levels also correlate with future health risks. A high BMI predicts a higher risk of chronic conditions like high blood pressure, heart disease, and certain cancers.

Its limitations

couple, retirement

BMI doesn’t account for age | iStock.com

Its downfall lies in its simplicity. Because it measures excess weight, not excess body fat, someone who is very muscular may have a high BMI and incorrectly be classified as overweight. A thin, inactive person may have a normal BMI but have more body fat than is healthy. In addition, the index doesn’t take into account age, ethnicity, and sex, which can influence the relationship between weight and height. For example, a 20-year-old person and a 60-year-old person may have the same BMI, but older adults typically have more body fat. A woman will also tend to have more body fat than a man with the same BMI.

Wonder where you fall on the spectrum? Here’s how to calculate your BMI.

Time to calculate

man standing on a bathroom scale

Man weighing himself | iStock.com

The Centers for Disease Control and Prevention have a great BMI calculator on their website. Simply plug in your height and weight and in moments the calculator will calculate your BMI. To determine yours by hand, divide your weight in pounds by your height in inches squared. Then, multiply the result by a conversion factor of 703. Written out, the equation looks like this: weight in pounds / (height in inches x height in inches) x 703 = BMI.

Understanding the results

 

man running on the beach on a sunny day

Man running on the beach | iStock.com

If your BMI is below 18.5 this means you are underweight for your height. Readings between 18.5 and 24.9 show that you are at a normal or healthy weight, while a result between 25 and 29.9 means you are overweight. If your BMI is 30 or higher, the result shows that you are obese. If your result does not fall within the normal, healthy weight category, it may mean you need to come up with a plan to either gain or lose weight.

If your reading showed you were underweight, talk to your healthcare provider to determine possible causes of your low weight and to decide if you need to gain weight. If your result said that you are overweight or obese, it may be time to come up with a weight loss plan. The first step is to make a commitment to lose weight and alter your current lifestyle. From there, set realistic goals, come up with resources for information and support, and monitor your progress.