Measure your head
Use measuring tape or string to measure the circumference of your head 1 cm above the eyebrows.If using a string, measure it end to end with a ruler.
Consider the shape of your head
You have already measured the circumference of your head, now consider its shape to find your size in the size guide. Do you have an oval or round head?
Find your size in the size guide table.
Find your size in the size guide according to your head circumference measurement and shape.