Despite what you may have heard, the average American woman is not a size 16. The reality of women’s clothes sizing renders any attempt to pin the metric to a single number void of any significance. A woman with a 31-inch (79 cm) waist can go home with pants of size eight, 10, 12, 14, or 16. It just depends on the brand.
A Quartz analysis of denim sizes in the Mall of America—and the waist circumferences those sizes actually fit—reveals that these fit labels are rendered all but meaningless through the industry’s variation in size. Women’s clothing retailers in the US do not conform to established standards, are not regulated, and actively use vanity sizing. The result is an extreme range in what brands consider a size 16. A 16 at A’gaci will fit women with a 31-inch waist, while the same 16 tag at Lucky Brand and Forever 21 will accommodate a woman with a 39-inch waist. Both are a size 16, but one will definitely disappoint in the fitting room.
In the 1950s, the American Society of Testing and Materials (ASTM)—a leader in standards development—first published their classification of women’s apparel sizing. The use of these specifications, however, has always been voluntary. Using anthropometric data, ASTM still reviews and updates the standards for the USA apparel industry, which includes standards for both plus-size and petite figures. Many manufacturers use the same numerical size codes, but with their own measurements. This ultimately results in a frustrating shopping experience for women of any size; and it makes classifying women by their fit a futile act.