I normally wear an 11 in various Crocs styles, so I ordered an 11. Unfortunately, it was too small buy just a tiny bit. I compared it to the size 11 flip flops I have to see what the difference was...and it's the lip of the heel. The flip flops have a lower lip (where your heel hits) so you can't feel it as much. These shoes have a higher heel lip, so your heel hits it more and feels weird. They didn't offer these in a bigger size, and I got such a great deal on them, that I just gave them to my mom. I'm still giving them three stars because they are cute and were comfortable--they were just too small for me.