I would actually have to say it depends on the Nike SB or the Jordan. For Jordans 8.5 is a perfect fit length wise for me. For Dunk Sb lows for example. Those are more like a 9 or a 9.5 due to the narrowness. If you have narrow feet, get .5 or a full size bigger in Dunks. The Zoom Tres also I would recommend a size up also. Hope this helps.