Usually I wear a US size 10 or 11, so I tried a 10 - it was HUGE! I reordered a 9.5, thinking with socks it might work. Still way too big for me. These are adorable shoes, they look like Danskos, and from what I can tell they are comfortable. I now have to return two pairs of shoes and decide if I want to try a third time. Amazon's customer service is superb, though, so the return process isn't a big problem.