All Size 8 Jeans Have the Same Measurements, Right? Wrong!

— -- If 12 inches is a foot and 16 ounces is a pound, then all size 8 jeans should have the same measurements, right?

Not so fast.

“Good Morning America” ordered size 8 boot cut jeans from seven different brands: Old Navy, J. Crew, Joe’s Jeans, American Eagle, Levi’s, Express, and The Gap.

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We asked two Oakland California teachers, Claire Hopkins and Valeria Haro, both self-described size 8s, to try on our jeans. Of the seven brands, each teacher said three of the size 8 jeans fit them properly.

For Hopkins it was Gap, J. Crew and Express.

For Haro, it was Gap, J. Crew and Joe’s Jeans.

Almost all the others were too big or, as Hopkins, a speech therapist and mother of three, described them, “too poochy.”Both of the women said that the American Eagle jeans were the furthest from a good fit.

With the American Eagle brand, Hopkins complained of at least 3 inches of extra room in the waist of the jeans, which became a gaping problem when she squatted down, something she does often with her students.

Hopkins said she would have to try a size 6 or maybe even a size 4 in the American Eagle jeans in order to find the right fit.

Measuring the Pants

With that much variation in fit described by our models, we asked the instructors at San Francisco’s Academy of Art University Fashion School to measure all the pants.

Terhi Ketola-Stutch, the school’s 3D design coordinator, found that the waist measurements ranged from 31 inches to 35 inches in our seven pairs of jeans, but that since the rise of the jeans was fairly diverse, the waist measurement discrepancies were more a product of style (i.e., how high-waisted are the jeans).

A more reliable gauge for the pants, according to Ketola-Stutch, was the hip measurements.

Joe’s Jeans were the smallest hip measurement, at 36 inches, while American Eagle jeans were the biggest, at 39.75 inches.Levi’s, Express, Gap and J. Crew were all 37 inches. Old Navy measured 39.25 inches at the hip.

In all, it was roughly a 10 percent variance in hip width for the seven pairs of jeans. Our size 8 teachers each preferred jeans that had a 36 to 37-inch hip width.

The leg circumference at the thigh was another relatively uniform place to gather fit measurements.

Ketola-Stutch found the smallest jeans, Joe’s, coming in at 21 inches and the largest, Levi’s, American Eagle and Old Navy, coming in at 23 inches.

The rest of the jeans all measured 22 inches or very close to 22 inches. Overall, there was a two-inch or roughly 10 percent variance among the pants.

Are There Any Sizing Standards?

When asked if there are any sizing standards in women’s fashion, Hersha Steinbock, merchandising instructor at the Academy of Art University Fashion School, explained that there really are not.

“There are standards within a brand that conform to what a customer wants and needs; specifically what that brand is targeting,” Steinbock told ABC News.

According to Steinbock, in the 1930s, the government set out to create uniform standards when mass production of clothing began. By 1983, however, the whole idea of standardization fell out of favor.

“Most brands never used the sizing standards and, today, we have what we have, which is diversity,” said Steinbock, who added that most fashion labels use their own standards as a proprietary advantage over other brands.

When I talked with the president of Levi’s, James Curleigh, he agreed.

“We invented blue jeans and we made the first pair for women in 1934," Curleigh said. "We’ve had our own sizing from the very beginning."

Curleigh also agreed that fit is always subjective and trying pants on is an important part of the process.

Curleigh’s company, Levi’s, has brought to market their Curve ID, which asks consumers to identify their body shape in a progressive online questionnaire and then suggests appropriate styles once their body type is determined.

One final thought: While vanity sizing has been much discussed, I think our very unscientific measurements show that there is a range of sizes and companies try to create choice but also some degree of consistency within their own brand to engender loyalty from customers.

I know what size I am in my favorite brands and, as a result, they are the only clothes I feel confident buying online. It was comforting to know that I’m not losing my mind with the discrepancies in fit I experience when our fashion experts explained that sizing is a marketing play, much more sophisticated than catering to our vanity, and it is a familiarity play in a world of many fashion choices.

American Eagle declined to comment to ABC News for this story. Joe’s Jeans and Levi’s each provided a statement to ABC News, both of which are copied below.

Levi’s Corporate Statement:

The future is fewer choices and a more simplified approach to find the perfectly fitting jean. Trial is critical component of finding the perfect fit. We’ve taken our Curve ID innovation one step further with the introduction of Levi’s Revel. Revel actively shapes a woman’s body with a four-way stretch fabric comprised of cotton, polyester, Lycra and DuPont’s Sonora fiber. We then print a proprietary liquid chemical formula on the fabric interior that regulates the level of stretch in strategic areas, providing structure, support and a figure-flattering shape to the jean, rather than simply uniform stretch. Inspired by the beauty and the compression wear industries, Levi’s® REVEL actively shapes the body to deliver a sexy, feminine fit enhanced by secret weapon technology making women look and feel confident. Revel is available in Bootcut, skinny and straight silhouettes.

Joe’s Jeans Corporate Statement:

At Joe’s we’re constantly evolving the collection – the styles, fits, washes, etc – to meet the needs and wants of our customers. For example, we took the classic straight leg and created a looser, slouched fit for those who prefer the “boyfriend” look. We found that the traditional bootcut was becoming a bit outdated, so the measurement in the leg and leg opening is smaller to offer a sexier take.