Body mass index (BMI) for adults

Adapted from U.S. Department of Health and Human Services (2000). Report of the Dietary Guidelines Advisory Committee on the Dietary Guidelines for Americans. Available online: http://www.health.gov

Use the chart to locate your height and weight. The shaded regions on the chart correspond to normal and overweight ranges based on body mass index (BMI). Keep in mind that this 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. People who are very muscular or those who have very little muscle may not get an accurate BMI by using their height and weight alone. Muscle weighs more than fat, so a muscular person may appear to have a higher BMI, or a frail, inactive person may have more body fat than is healthy.

For adults 20 years and older:

• A BMI below 18.5 (shown in white) is considered underweight.
• A BMI between 18.5 and 25 (green) is considered a normal weight.
• A BMI between 25 and 30 (yellow) is considered overweight.
• A BMI of 30 or higher (red) is considered obese.
• 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. If you are Asian, your health may be at risk with a lower BMI.¹

According to federal guidelines, a clinical diagnosis of obesity also includes a determination of your waist circumference and risk factors.

• If you are within the normal BMI range and your waist measurement is lower than the cutoff, maintain that weight and check your fitness level, blood pressure, and cholesterol levels.
• In men, a waist circumference greater than 40 in (101.6 cm) is considered a health risk. Women who have a waist size larger than 35 in (88.9 cm) are considered at risk. In Asian people, health problems are seen with a smaller waist size. In Asian women, a waist size of 32 in. (80 cm) or more raises the chance for disease. In Asian men, a waist size of 36 in. (90 cm) or more raises the chance for disease.²
• If you are in the overweight (BMI of 25 to 29.9) or obese (BMI of 30 or higher) category and your waist measurement is higher than the cutoff level, talk to your doctor about other risk factors you may have, including type 2 diabetes, smoking, high blood pressure, high cholesterol, and being inactive. If you have two or more risk factors, your doctor will probably advise you to lose weight and to change your eating and physical activity habits to reduce your risk factors for blood vessel disease, such as coronary artery disease (CAD), peripheral arterial disease (PAD), and coronary vascular disease (CVD).

¹Razak F, et al. (2007). Defining obesity cut points in a multiethnic population. Circulation, 115(16): 2111–2118.

²Purnell JQ (2005). Obesity. In DC Dale, DD Federman, eds., ACP Medicine, section 3, chap. 10. New York: WebMD.