One perplexing mystery that begs attention for us women is: why doesn’t this piece of clothing fit me? It’s not because you’ve gained or lost weight. It’s not because your garment has shrunk. It’s definitely not because you misread the label when you bought it. It even looks like your significant other got the size right too . . .

So what’s up with that? To demonstrate the reality of off-sized clothing for women, Vox conducted an experiment in finding the right fit. For starters, most ladies’ clothing options use size numbers instead of actual measurements here in the U.S. It can get sketchy if you’re not sure of either one.

Marilyn Monroe was used as an example of how broad her size range was when matched against her actual measurements. In the example, her bust, waist and hip measurements would qualify her to be either a 4-6, 6, or 8 if she shopped at our stores today. Fashion professor Lynn Boorady points out that in her time, Marilyn Monroe was considered a size 12, which today would be a 6.

What’s a girl to do in the midst of all this confusion? The young lady in the video bought three pairs of size 4 jeans from three different stores: Zara, Topshop and Forever 21. When she held all the jeans together to compare them, it was clear that all three were three separate sizes. Which is the true size 4?

The pair from Zara were too big on the experimenter, leaving her to brand them as not being a size 4 at all. Topshop’s jeans earned a round of applause for being a great fit without any hassle. The last pair tried on were from Forever 21 and she could barely get them zippered and buttoned. Not cool.

To illustrate where the difficulty started, we had to travel back in history. Right around the Civil War here in the states, men’s uniforms became the standard for sizing, followed by suits. When clothes were first manufactured as “ready-made”, it was based on the chest measurements and estimated proportions of guys.

As we rolled into the 19^th century, mass-produced clothes were the norm. As noted in the video, a 1939 study sought to level the clothing playing field for women. Fifteen thousand ladies participated to help determine proper measurements for garment construction. The problem was that the calculations used to define the measurements weren’t based on an average, or a diverse set of women. Sizes were off.

The study was updated over the years until it was finally squashed in the early ‘80s. Clothing companies started dropping the sizes down around that time to appeal psychologically to the consumer. Called vanity sizing, it deflated sizes so that a 12 became an 8, and a size 4 turned into a 0. All in all, it’s marketing.

Today, there is no standard, accurate set of measurements for women’s clothing. Instead apparel makers come up with their own standard based on their sales demographic. As our narrator mentioned, that’s why you see varied sizing among brands housed under one company.

If you’re used to shopping around a lot, you might be aware of which items tend to run bigger or smaller for your frame. If not, your best bet is to try stuff on. Good luck out there! What are your thoughts on women’s wear sizing? Have you experienced shopping frustration? Tell us in the comments!