I wear a size 10 normally but I took everyone's advice and ordered a size 11.  It fits perfectly.  I have never worn such an unusually comfortable light weight supportive shoe.  The box was so light that I thought it was empty.  The shoes are as flexible as ballet shoes, you can bend them in half.  THe ball of the foot is very padded as is the heel.  I wear these to zumba in and I am so impressed I might just buy another pair.  Excellent shoe.