Ordered size 8 at first, since that usually works. It was a bit tight over the toes, so I ordered size 8.5. These were good in the toes, but a bit<br />large at the heel. So, after trying them on (both pairs ) many times, I found the smaller size was spreading out a bit, and they were comfortable<br />when I had bare feet. The 8.5 size are perfect when I use sport socks. So, I decided to keep both pairs: the size 8 for the summer and the larger size for the cooler weather or when doing sports with socks on.