The average female waist size varies by nationality. According to a 2012 study in the Journal of the American Medical Association, the average waist size for American women is 37.8 inches. The average waist size in British women is 33.43 inches, states a study cited on the BBC in 2012.
According to NCBI, the average waist size for French women surveyed in 2006 was 33.15 inches. A study of about 3,000 British women cited in the Telegraph in 2011 finds the average waist size to be 30 inches. The 2012 Journal of the American Medical Association study is based on over 32,000 people, and the study cited on the BBC in 2012 is based on about 54,000 people.