I like my tops and sweatshirts to be BIG, not tight, so I order 3Xs normally. The 3X size at Lilicloth is a size 1X or size 18W in American sizes. Oh, they fit, but are way too snug, not at all the way I like them. Too much trouble to return them, but I want to warn any new people who are going to order any of the tops or novelty sweatshirts to be aware to order at least 2 sizes larger than their "normal" sizes. Also, be aware that if you order more than one item, they will arrive at different days, but all 5 of mine arrived within 2 weeks. Love the tops -- hate the sizing!