What is BMI, and Why Does It Matter?

Your Body Mass Index, or BMI, is a good indicator of whether you’re at a healthy or unhealthy weight in relation to your height.




Your Body Mass Index, or BMI, is a good indicator of whether you’re at a healthy or unhealthy weight in relation to your height. This numerical value is calculated by dividing your weight in kilograms by your height in meters squared (kg/m2). You can use our BMI calculator, available online at heart.org/bmi, to calculate your BMI. Here’s what the numbers mean:

⇒ A BMI less than 18.5 kg/m2 is considered underweight.

⇒ A BMI between 18.5 kg/m2 and 24.9 kg/m2 is healthy.

⇒ A BMI of 25 kg/m2 to less than 30 kg/m2 is defined as overweight. People with BMIs in this range are usually about 10 percent over their ideal weight and have an increased risk of heart and blood vessel disease.

⇒ A BMI between 30 kg/m2 and 40 kg/m2 indicates obesity, which is about 30 pounds or more overweight. People in this range have a high risk of cardiovascular diseases.

⇒ A BMI over 40 kg/m2 indicates extreme obesity.

The BMI assessment isn’t for everyone and may not be the best method for those who are under age 20, highly trained/athletic, pregnant or breastfeeding. If any of these apply to you, ask your healthcare provider about other ways to assess your body composition.

If you find your BMI is over 25 kg/m2, talk to your healthcare provider about the best ways to drop those extra pounds.

 
Edit ModuleShow Tags

AD: American Heart Association logo. American Diabetes Association logo. Checked box. I'd like to take care of my diabetes and lower my risk of heart disease and stroke. Know Diabetes by Heart logo. Button: Join Now


 

AD. American Heart Association Support Network. Everyone's diagnosis story is different and sharing yours can help others. Join the Support Network and share your experience. heart.org/SupportNetwork


 

AD: American Heart Association logo. Symptoms. Always feeling tired isn't normal. Learn the signs of Heart Valve Disease.


 

AD. American Heart Association logo. Know your blood pressure numbers. And what they mean. Gain Control. button: learn more.


 

AD. Heart Insight. Get the app for free.


 

Edit ModuleShow Tags

Special Topic Supplements

Edit ModuleShow Tags

Departments

Heart News

Heart health news you can use about new scientific findings, public policy, programs and resources.

Heartfelt

Articles, poems and art submitted by heart disease survivors and their loved ones.

Life's Simple 7

Improving your health is as easy as minding seven simple health factors and behaviors. Tips and information to help you improve your health and enhance your quality of life.

Life Is Why

Everyone has a reason to live a longer, healthier life. These heart patients, their loved ones and others share their 'whys'. We'd love for you to share yours, too!

Simple Cooking

Cooking at home can be a daunting task, but a rewarding one for your diet and lifestyle (and your wallet). Making small changes in your diet is important to your heart health. Here are simple, healthy and affordable recipes and cooking tips.