I wear an 8 and in Dansko, I'm a 39, which says it fits 8.5-9. I have many pairs of Dansko clogs and sandals and am always a 39.
I wear an 8 1/2 to a 9 in either a running shoe or a dress shoe and this particular shoe/sandal comes in Euro sizes and I ordered size 40 and it fits great!
I hope this helps. It is a great shoe.
I wear a 7.5 US shoe/sneaker and I wear 38 in Dansko...