Plus sizes are different than regular sizes, both in name and in cut. The cut is a little more flattering for those with the shape of a Paleolithic fertility goddess. I personally tried on UT size 18 jeans and UT size 18W jeans, and they are identical from mid-hip down but from mid-hip up the plus size had a ton of extra room in the belly and waistband. If someone is in that gray area where the sizes overlap, then a plus size X is the same size as regular size XL and a plus size 1X is the same as a regular size XXL. 2X is roughly a size larger than an XXL.