Body mass index (BMI) for adults

Adapted from: U.S. National Heart, Lung and Blood Institute; U.S. National Institutes of Health (2000). The Practical Guide: Identification, Evaluation, and Treatment of Overweight and Obesity in Adults. (NIH Publication No. 00-4084). Available online: http://www.nhlbi.nih.gov/guidelines/obesity/prctgd_c.pdf

Use the chart to locate your height and weight. The shaded regions on the chart correspond to weight ranges based on body mass index (BMI).

For adults 20 years and older:

• A BMI below 18.5 (light blue) is considered underweight.
• A BMI of 18.5 to 24.9 (green) is considered healthy.
• A BMI of 25 to 29.9 (yellow) is considered overweight.
• A BMI of 30 to 39.9 (red) is considered obese.
• A BMI of 40 or higher (purple) is considered extreme obesity.

Keep in mind that BMI is only a guide. It is not a tool to determine ideal body weight. It is a tool to help you see whether your weight is increasing your risk for disease. BMI does not work as well for people who are very muscular or those who have little muscle. A muscular person may have a high BMI but still have a healthy level of body fat. A person with very little muscle may have a normal BMI but have unhealthy levels of body fat.

If you are Asian, your health may be at risk with a lower BMI.

A person who has a large change in BMI, even if he or she is not overweight or underweight, should be evaluated to find the cause.