I occasionally buy some basics at Gap and there is absolutely no consistency in sizing. There is no rhyme or reason to sizing labels and the styles are mostly designed to flatter fatties. A garment with a specific size will fit differently when bought only a few months later. Two different garments with the same labeled size should have a similar fit even if they have a different style but they won't. Even the same garment and size in the same lot on the same shelf will very often fit differently - its now borderline necessary to try on more than one of the same garment with the same label size as they will quite likely fit differently. Its almost like they don't whip the children in their sweatshops hard enough to get it right. Maybe customers just don't give a shit so they just sew-in any random number size?