I ordered this item because my son had grown out of his size 4 Quiksilver long-sleeve rashguard. I ordered a size 6, but it ended up being only larger in the torso width and the same size as the size 4 everywhere else. The size 7 was much better. I would recommend ordering a size up! Overall, I love these rashguards and feel they do an excellent job of keeping the sun off of my son.