Okay so, I'm typically an American 9.5 with wide/flat feet (ugh.) My foot is probably about the length of a 9 or 8.5 but the width thing def makes me a 9.5. Dr. Marten's don't make half sizes so when it comes to the boots I'm a UK 7 (US 10), but my gut told me that since these are sandals and width doesn't come into play, a UK 6 (US 9) would do. Bingo! I was right.
The fit is great on the foot itself. BUT, the ankle strap rubs the back of the ankle and on their first dry run, I got cuts on the back of my ankles. :( Luckily, I know where to buy really good heel cushions made out of the rubbery material that stay on very very well and only cost a few dollars. Problem solved!
Bear in mind, though, these are heavy. Not tremendously, but more than the average wedge.