The reason for this is not to frustrate all of us (even though it can sometimes feel that way), but rather it is a practice implemented by each designer as a method of branding their product. Every designer strives to give their jeans a unique style and feel. The goal is to have consumers find their jeans and decide that they are the "perfect fit", thereby gaining them loyal customers that adopt their brand as their favorite.
In order to help you gauge how sizes translate from regular US sizes to "designer sizes", we've created details pages for each of our featured brands. These pages contain information pertaining to the different styles available from the designer as well as US size to waist size ratio. To access that info, click the appropriate link:
Chip and Pepper
Paige Premium Denim
Paper Denim and Cloth