I used the shoe specific size guide to order for a US 6.5, UK 5, Eur 37 and what I received in the mail is a shoe that has an inside label that says: US 6, UK 6, Eur 39.5.  I was using the centimeters as a guide and the Eur 37 made sense. Needless to say that the shoe is at least a size and a half too big. I will need to return.