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.
Physical attractiveness
Both men and women judge women with smaller waist-to-hip ratios more attractive. Ethnic groups vary with regard to their ideal waist-to-hip ratio for women, ranging from 0.6 in China, to 0.8 or 0.9 in parts of South America and Africa, and divergent preferences based on ethnicity, rather than nationality, have also been noted. A study found the Machiguenga people, an isolated indigenous South American ethnic group, prefer women with high WHR (0.9). The preference for heavier women, has been interpreted to belong to societies where there is no risk of obesity.