To measure your head, simply take a tailor's tape measure and wrap it around your head just above the ears, making sure that you are not pulling too tightly as this could result in an inaccurate measurement. Getting a measurement in centimeters is the most accurate method of measuring your head as sizing for different companies can sometimes vary. Please view our table below for a clearer explanation of sizing variations.
| Metric cm | UK Hat Size | US Hat Size | |
| Small | 54 - 55 | 6 5/8 - 6 3/4 | 6 3/4 - 6 7/8 |
| Medium | 56 - 57 | 6 7/8 - 7 | 7 - 7 1/8 |
| Large | 58 - 59 | 7 1/8 - 7 1/4 | 7 1/4 - 7 3/8 |
| X Large | 60 - 61 | 7 3/8 - 7 1/2 | 7 1/2 - 7 5/8 |
| XX Large | 62 - 63 | 7 5/8 - 7 3/4 | 7 3/4 - 7 7/8 |