Size Guide:

Fetty slides fit true to size - pick the size you normally wear.
US (M)  US (W) (IN)
4 6 8 5/6
5 7 9 1/6
6 8 9 1/2
7 9 9 5/6
8 10 10 1/6
9 11 10 1/2
10 12 10 5/6
11 13 11 1/6
12 14 11 1/2
13 15 11 5/6
14 16 12 1/6
15 17 12 1/2