‘Vanity sizing’ makes shopping for clothes a difficult process

When it comes to shopping for clothes, many Americans don't know what size they are. There is no standardized sizing, which has led to fitting room nightmares and billions of dollars in returned clothing.

Your clothing size may be a better measure of your mind than your waistline.

For shopper and fashion blogger Christine Cameron, “What size are you?” is a complex question.

"So, if I go to H&M, for instance, I will grab anywhere from a four to and eight. Now, if I went into J. Crew, I could wear anything from a double zero to a two,” Cameron said.

This fitting room frustration comes from vanity sizing - clothing brands putting smaller numbers on tags while Americans get bigger.

Fashion Institute of Technology Professor Shawn Carter said it's all a mind game.

“Vanity sizing is a way for luxury brands and other brands in fashion to help a customer feel good about themselves by saying ‘you're a size two,’ but when you look at their measurements of bust, waist and hip, they could be a size six or even a size eight,” Carter said.

What was a size eight in 1958 would be considered a size 14 today.

Giving larger clothes smaller numbers has forced manufacturers to create new sizes like zero, and even, double zero.

One way to know your true fit is to measure your bust, waist and hips.  Most retailers provide fit charts online, so you can translate your measurements to their sizes.