I would have expected 3XL to fit a TAD bit larger, so I think it might run just a little bit small. I typically wear a 2xl-3xl top and this feels more like a 2xl (i purchased 3xl, for ref I also wear 18 bottoms). This is a really thick, nice feeling top! I appreciate the sleeve length, the cut is flattering and the pattern looks just like the photo. I really love this top, my first floral pattern I actually like.