that's so weird about sizing, because I have way too many Ibex pieces and a few SW, and the fit seems to be consistent. I'm a true Small in Ibex topss. Compared to athletic wear it's true they run large, but compared to street wear and anything I have from SW, they're smaller. I have a Small SW tank that just hangs on me, where my Small Ibex tank ... I hate to even wear it because it's so perfect for everything, and they don't sell them any more!