This Is Why A Different Size Fits You At Every Single Clothing Store

There's an adage tossed around by sorority girls who own Audrey Hepburn posters and plus-size lingerie campaigns that Marilyn Monroe, bombshell extraordinaire, was actually a size 12. Like most things that sound too good to be true, it's unfortunately a load of crap.

A new video from Vox, the site best-known for its "explainer" articles breaking down complicated subjects into easy-to-understand, factual kernels, tackles the women's clothing industry. Boy, is it a whopper.

Clothing sizes may have started with the measurements of enlisted men who just needed uniforms that fit well enough, but manufacturers had a much more complicated situation when it came to women. The male body is basically the same circumference wherever you measure, from the chest on down, but women have breasts, hips and a whole bunch of other curves Beyoncé has written songs about. That's where things get complicated.

Over time, manufacturers have found customers are more likely to buy (and not return) items with smaller numbers written on their tags, leading to a phenomenon called "vanity sizing." Your size 4 dress and size 8 jeans are lying to you, essentially — particularly if you're shopping in a store that tweaks sizes to better fit its demographic. That's why you'll always be a smaller size in an Old Navy dress than one from Topshop. Miss Marilyn might have been a midcentury size 12, but today's equivalent is closer to a 4 or 6. Darn it.

At least now, when you're trapped in the sickly, recycled air of a Zara while squeezing into a pair of jeans threatening to pop, you'll know how this whole tragedy came about.