7 3/8 7 1/2 7 1/2 7 5/8 2XL 62cm 63cm 24 1/4 24 5/8 7 5/8 7 3/4 7 3/4 7 7/8 3XL 64cm 65cm 25 25 1/2 7 7/8 8 8 8 1/8 Tips for getting the right size MEASURE Measuring for your head size is both an art and a science You can use a tape measure or a length of string that you will have to hold up to a tape measure