Fact: The average American woman is around a size 16-18. Which means that some women fall below that, and some fall above.

Yet many fashion brands that don't sell plus sizes still cap their sizing at a 14 — and many of the ones that do don't go above a 22... or sometimes, even a 20.

And we wanted to know why.

ENSURING QUALITY CONTROL

clothes hangers
photo: Getty Images/Chris Jackson

"Designers factor a whole range of variables into their decisions about their size grading," said Melinda Parrish, a Ford model and body-positivity advocate. Many rely on market data to pinpoint the size range that will see the most demand, she said, and newer designers often start with a smaller range "in order to ensure quality control."

H&M, which is notoriously anti-plus-size, goes up to a 4X — but anything above a 2X is only available for jersey and knitwear apparel (the stretchy fabrics). Forever 21 goes up to a 3X, but its 3X is the same size, measurement-wise, as Missguided's size 20. And Uniqlo's largest size 2X is very close in measurement to Zara's largest size 18.

But none of these, you've probably noticed, are new designers.

TOO MUCH SUPPLY... TOO LITTLE DEMAND?

In fashion, as with any business, the goal is profit. And, as they say, you have to spend money to make money. But many brands believe spending money on a stock of larger sizes isn't worth it if the inventory is going to sit, unpurchased, in a warehouse.

"Many customers who wear size 14 and above, and more so size 22 and above, find they are left with very little by way of choice in fashion, let alone choice of something that fits them," B.G. Krishnan, founder and CEO of eShakti, an online retailer that sells sizes 0-36W and custom sizes, told Revelist.

"The more sizes a brand offers, the more the inventory it has to maintain and therefore the more that remains unsold at the end of the season," he continued. "This affects their profitability. ... So they cut their risk by limiting the sizes they offer. This can be frustrating to many customers whose sizes are left out."

'I DON'T WANT HER WEARING MY CLOTHES.'

plus size girls
photo: Getty Images/Loic Venance

Unsold inventory is one thing, but that's not what's preventing some designers from making clothing for bigger bodies, Tim Gunn pointed out in an op-ed for The Washington Post in September 2016:

"There are 100 million plus-size women in America, and, for the past three years, they have increased their spending on clothes faster than their straight-size counterparts. There is money to be made here ($20.4 billion, up 17% from 2013). But many designers — dripping with disdain, lacking imagination or simply too cowardly to take a risk — still refuse to make clothes for them."

So, it seems, it's not actually a matter of money. Gunn continued:

"I’ve spoken to many designers and merchandisers. ... The overwhelming response is, 'I’m not interested in her.' Why? 'I don’t want her wearing my clothes.' Why? 'She won’t look the way that I want her to look.'” ... Some haven’t bothered to hide their contempt. 'No one wants to see curvy women' on the runway, Karl Lagerfeld, head designer of Chanel, said in 2009."

OVERCOMING A PRODUCTION BARRIER

Because the majority of clothing is produced overseas, these factories have "certain configuration to cut clothes for sizes 14 and below, and a different configuration for larger sizes," Parrish noted.

For example, she said, Rachel Pally only sells clothing up to a size 22, but it starts at a size 2, and that's a huge size range. "Rachel Pally has overcome a very significant production barrier by creating a size-inclusive line," said Parrish, who also noted that "she may even have to work with multiple factories to achieve this."

Most clothing lines that go above a 22 are the retailers that tailor specifically to plus-size customers: Torrid goes up to a size 30, Eloquii to a 36W, Lane Bryant to a 28. Unfortunately, for plus-size consumers, that may be the best the industry can do for now.