Measure your head using a sewing tape measure for the most accurate result. If you don't have a sewing tape measure use a piece of string and then measure it flat against a ruler or builders tape measure. The Below measurements are taken from inside our hats so match these as close as possible to your head measurements. 

All our hats have a size adjustable sweatband so there is a 2cm tolerance for each size. 

Size - cm A B C
53cm - Kids 4 - 9yrs 53 29 27
55cm - Kids 10+ / Adults S 55 31 28
57cm - Adult M 57 32 28
59cm - Adult L 59 33 28
 51cm - Adult XL 61 34 28