I wear a 13-13.5 US and their 46cm (I think it's a 46, maybe a 48) shoe fits just as it should... although I'm of no help now, so here's the link to their size chart:
http://www.specialized.com/media/pop..._Shoes2008.gif
EDIT: I looked, mine are 48 and fit like my size 13 adidas tennis shoes.