A person's BMI, or body mass index, is based on height and weight. It's often used to determine if a person is underweight, normal weight, overweight, or obese. But BMI doesn't consider muscle mass. Follow the links below to find WebMD's comprehensive coverage about how BMI is calculated, what it means, how to measure it with our innovative BMI Plus Calculator tool, and much more.
Read about BMI, waist size, and other measurements -- and why some fall short in gauging obesity.