Havaianas sizes are in Brazilian, we have converted the sizes so you just need to pick your UK size.

UK Size Brazil Size Size in cm EUR size
2 33/34 22.5 35/36
3/4 35/36 23.5 37/38
5 37/38 25 39/40
6/7 39/40 26.5 41/42
8/9 41/42 27.5 43/44
10/11 43/44 28.5 45/46
12 45/46 30 47/48