The Average American Woman Wears a Size 16, Study Says

American women are on average between a misses size 16-18, or what is considered a plus-size 20W, according to a new study in the International Journal of Fashion Design, Technology and Education.

University of Washington researcher Deborah A. Christel and Susan C. Dunn of Washington State University compared publicly available data – along with waist measurements of over 5,500 women above the age of 20 collected by the CDC – to women’s Misses’ clothing sizing standards set by the American Society for Testing and Materials, reported Forbes.

Christel and Dunn concluded that women’s waist size has grown by 2.6 inches over the past 21 years.

Forbes notes, however, that it is difficult to nail down women’s sizing, as there is no public source for the body measurements necessary to fit clothing.

Further, the research doesn’t necessarily account for body shape, waist to hip ratios – and the total lack of standard sizing.

Industry standards for clothing sizes are voluntary, said Forbes.

“I understand that all research has its limitations,” Christel told Forbes. “Time and page space in journals also provides limitations in research and reports.”

She adds, “We wanted to use publicly available data that was collected in a reliable scientific manner. Also, every clothing company has its own sizing chart and we recognize that we are making a generalization based on two very specific data sets. We used the measurement that made the most sense to us and that was agreed as acceptable by peer reviewers in our discipline.”

The study results come as Refinery29 launches the 67 Percent Project. The project is based on the data that 67 percent of women in the United States wear a size 14 or higher.

Orange is the New Black actress Danielle Brooks, who is an ambassador for the project, said in an Instagram video, “67 percent of women are plus size, but only two percent of them are seen in media, magazines and the plethora of other things we see every day. It is time for all of us to be seen, to be heard.”

Refinery29, in conjunction with the project and partnership with Getty Images, is making stock imagery of plus-size women available for free for use across blogs and major outlets.

This article originally appeared on People.com