I normally wear a size 10 and a half or an 11 - depending on the manufacture of the shoe. But I ordered a size 11 of this Croc because that is what I most often end up wearing in any shoe. But, this Croc in a size 11 is slightly too small, making the wearing of the thinnest socks a must - even with no socks the shoes are too tight. Since they don't come in half sizes, I went ahead and kept them figuring that a size 12 would be too big. It is also important to know that these are not an easy slip-on loafer. There is an elastic material that causes the heel to pull toward the front of the shoe, making it a struggle to get the shoes on. My hope is that after wearing for awhile, they will stretch out a little - making them more comfortable to wear and easier to get on. I would have to say that I would not buy these again.