To find out your hat size, you need to determine the circumference of your head and this is very simple as detailed below: take a measuring tape and firmly, but not too tightly, wrap the tape around your head. Start from the forehead approximately 2 cm above the eyebrows and wrap your head 1 cm above the eyebrows. With the measurement obtained, compare it to the size chart and you will be able to determine your hat size. You can watch an explanatory video at the bottom.