Unfortunately these sandals come in whole sizes only.  My feet being size 10, I ordered the size 11 which seems larger than just a half size too big when I wear them.  I didn't want my feet squashed into a size 10 but now I'm thinking that size would have been more appropriate, given that these seem to be sized a bit large.  But even being a bit large, they are comfortable, mostly because the back closure holds everything firmly in place.