Havaianas Size Chart

Womens

US sizes = Brazil sizes

5/6 = 35/36
7/8 = 37/38
8-10 = 39/40
10/11 = 41/42

Mens 

US sizes = Brazil sizes

7/8 = 39/40
9/10 = 41/42
10-12 = 43/44
12/13 = 44/46