If you are in between sizes, or have a narrow foot, we recommend sizing down a half size. 

US 5 5.5 6 6.5 7 7.5 8 8.5 9 9.5 10 10.5 11
EUR 35.5 36 36.5 37 37.5 38 38.5 39 39.5 40 40.5 41 41.5