These are great, comfy shoes but I had to send them back because they were just a little small for me. I wear a size 8M most times and occasionally an 8.5M. I ordered a size 39 and they fit like a glove -- when what I really wanted was room to wear a pair of medium weight socks with them. My heel was about 1mm away from dangling over the back end and even with the elastic goring, it would have been tough to wear these with anything thicker than a trouser sock or tights.<br /><br />I do plan to reorder eventually and try the 40. They were the most comfortable too-small shoes I've ever put on. I'm hoping in one size up they'll be keepers.<br /><br />UPDATE: I bought the 40 and it works out fine for me, a somewhat wide 8-8.5 US, with a high arch and instep. There's room for a medium weight sock. The only thing I don't like, hence the 4 vs 5 stars is the arch support. The shoe is very cushy, but the arch doesn't hit me perfectly so I don't feel supported. With socks, I think it'll be okay.