| Head circumference in cm | 56 | 57 | 58 | 59 | 60 | 61 | 62 | 63 |
| World | M | M | L | L | XL | XL | XXL | XXL |
| UK | 6 7/8 | 7 | 7 1/8 | 7 1/4 | 7 3/8 | 7 1/2 | 7 5/8 | 7 3/4 |
| USA | 7 | 7 1/8 | 7 1/4 | 7 3/8 | 7 1/2 | 7 5/8 | 7 3/4 | 7 7/8 |
How to measure exactly head circumference in cm: to determine the hat size, measure the
circumference of the head (in the height of the forehead above the eyebrows).
The measure in cm thus determined corresponds to the European system.