# What Is BMI?

## Use a BMI Chart or Calculate BMI With Our Gadget

Wondering what is BMI? A BMI chart may make it clearer or use our gadget to calculate BMI, body mass index for your height and weight.

Let's start with the basics... BMI is an abbreviation that stands for a measurement scale called Body Mass Index. BMI is a number calculated by comparing your weight and height. BMI is considered a reliable predictor of body fat for most people and is used to screen for weight categories that may lead to health problems.

There are more reliable ways to measure body fat, such as skin fold thickness calipers, underwater weighing or even an x-ray called dual energy x-ray absorptiometry (DXA). But those methods are expensive and not easily accessible to most people. So BMI is a fast... and FREE... method to help you figure out how bad things really are.

However, realize that a BMI is just an assessment tool. It won't tell you if you have any specific health problems. You'd need to see a doctor and probably have a more thorough examination and other testing. But at least the BMI may get you moving in the right direction.

### How to Calculate BMI

If, like my husband, you enjoy doing math, you can figure your body mass index out yourself by using this simple formula:

Weight in pounds/(Height in inches)2 x 703 = BMI

Or here's another way to write it:

Weight in pounds x 703
(Height in inches)2

Example: Weight = 150 lbs, Height = 5'5" (65")
Calculation: [150 ÷ (65)2] x 703 = 24.96

If math isn't your thing, then you might find it easier to calculate BMI using our little widget:

You'll see some interpretations for BMI scores in the widget above, but here's another way of looking at it:

BMI
Weight Status
Below 18.5 Underweight
18.5 – 24.9 Normal
25.0 – 29.9 Overweight
30.0 and Above Obese

Some BMI charts I've seen go on to provide BMI scores matched up to "super obese" and "super super obese", but really what's the point? Once you're over a BMI of 30, you should know you're already in trouble and it's time to make changes in your life to get healthier. Right?

### A BMI Chart

OK... one last way to look at BMI, and this is the easiest yet... no effort required from you at all except to read.

Just scan the BMI chart below to see where you fit. First, find your height on the left side of the chart. Then, reading across on that line, look up and find your weight along the top. The number at the intersection of your height row and your weight column is your BMI!

For instance, I am 4'11" and 135 pounds, so my BMI is a bit over 27, which puts me in the Overweight category. Make sense?

I hope the BMI chart and other tools on this page have helped you calculate your BMI and answered your question about "What is BMI?" But if you still have questions related to what is BMI (or something else), feel free to visit our Ask a Nurse or Ask a Doctor pages.

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