Waist-to-hip ratio (WHR) is the ratio of your waist circumference to your hip circumference (calculated by dividing the waist circumference by the hip circumference). WHR is a measurement tool that looks at the proportion of fat stored on your waist, and hips and buttocks. Weight concentrated around the middle is often referred to as an “apple” shape; whereas, weight concentrated around your hips is referred to as a “pear” shape.

In many cases, persons with extra weight located around the middle are at higher risk for diseases such as heart disease and diabetes than those who carry weight around their hips and thighs. Abdominal fat, when out of proportion to total body fat, may be considered an indicator of health risks. A waist circumference measurement of over 35 inches in women and over 40 inches in men may increase risk because of the fat distribution.

The Body Mass Index (BMI) is more often used as the standard tool to measure overweight and obesity than the WHR.

Research shows that people with "apple-shaped" bodies (with more weight around the waist) face more health risks than those with "pear-shaped" bodies who carry more weight around the hips.