I always wear a 7.5 in any shoe. With these shoes, I had to exchange the 7.5 for a size 7 and even then there's a great deal of room in the toe of the shoe but a 6.5 would be too small. The tongue of the shoe is a thin material that points directly into your ankle so unless you're wearing higher socks then these would rub a sore spot in your ankle. I will be returning these for a full refund.