I wear a size 13 in Merrell Trail Glove 4. I wear a size 12 in Converse. dressed and not undressed. However, having personally tested the style, I'm going to try the Xero Mesa Trails at 14. The exposed straps are an issue since I do trail runs from time to time. And I'm not a fan of this style. I'm also considering trying the Altra Lone Peak 6, but my concern is that it has a stack height of 25mm (feet to floor) versus 11.5mm on the Merrell Trail Glove or 12mm on the Xero. Mesa Trail.