Waist–hip ratio
The waist-hip ratio or waist-to-hip ratio (WHR) is the dimensionless ratio of the circumference of the waist to that of the hips.
This is calculated as waist measurement divided by hip measurement (W ÷ H). For example, a person with a 30″ () waist and 38″ () hips has a waist-hip ratio of about 0.78.
Waist
The waist-hip ratio equals the waist circumference divided by the hip circumference. Practically, however, the waist is usually measured at the smallest circumference of the natural waist, usually just above the belly button. In case the waist is convex rather than concave, such as is the case in pregnancy and obesity, the waist may be measured at a vertical level 1 inch above the navel. It is important to note that variables such as posture significantly influence the measurement of the waist, and therefore any measurements for a group need to maintain a constant posture between the subjects.