Sizes are really weird, anyway. Here's a comparison of size 12 dimensions that I got from 3 different store websites: Old Navy, Gap, and Banana Republic. I think all 3 of these companies are actually one corporation, BTW, they just have slightly different product mixes and price spreads. Again, these are all size 12's:
Old Navy: waist 31.0", hips 41.5"
The Gap : waist 30.5", hips 40.5"
Bana.Rep: waist 30.5", hips 41.5"
And just for comparison, here's 2 other popular retailers, size 14:
Ralph Lauren : waist 31.5", hips 41.5"
Tommy Hilfiger: waist 31.5", hips 42.5"
So Old Navy calls their jeans a size 12, and Ralph Lauren calls almost the same measurements a size 14. Guess which retailer is making higher sales numbers and more profits? Right you are. It's called "vanity sizing" and it's all over the industry. But hey, it gets me too, every time. I've now got a pair of size 12 Old Navy jeans in my closet.
You can have my lower-sized jeans when you can rip them from my cold, dead thighs...
