Today, 64.5 percent of adults in the U.S. are overweight or obese. How do you know if you are among them? Two simple measures, body mass index (BMI) and waist circumference, provide useful estimates of overweight, obesity, and body fat distribution.

Health care providers use body mass index (BMI) and waist circumference measures to assess a person's risk of developing diabetes, heart disease, or other health problems. This fact sheet tells you how to measure your BMI and waist circumference, and what these measures mean for your health.

A BMI of 18.5 to 24.9 is considered healthy. A person with a BMI of 25 to 29.9 is considered overweight, and a person with a BMI of 30 or more is considered obese.

Because BMI does not show the difference between fat and muscle, it does not always accurately predict when weight could lead to health problems. For example, someone with a lot of muscle (such as a body builder) may have a BMI in the unhealthy range, but still be healthy and have little risk of developing diabetes or having a heart attack.

BMI also may not accurately reflect body fatness in people who are very short (under 5 feet) and in older people, who tend to lose muscle mass as they age. But for most people, BMI is a reliable way to tell if your weight is putting your health at risk. Use our BMI Calculator to find your BMI and also see WC Waist Measurement as well.