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.
Female body shape
Many studies indicate that WHR correlates with female fertility, leading some to speculate that its use as a sexual selection cue by men has an evolutionary basis. However it is also suggested that the evident relationships between WHR-influencing hormones and survival-relevant traits such as competitiveness and stress tolerance may give a preference for higher waist-hip-ratios its own evolutionary benefit. That, in turn, may account for the cross-cultural variation observed in actual average waist-hip-ratios and culturally preferred waist-to-hip ratios for women.