Measure the circumference of your head to determine your hat size.
| Head Measurement (inches) | Hat Size |
| 18 3/4 | 5 7/8 |
| 19 | 6 |
| 19 3/8 | 6 1/8 |
| 19 3/4 | 6 1/4 |
| 20 1/2 | 6 3/8 |
| 20 3/4 | 6 1/2 |
| 21 | 6 5/8 |
| 21 1/4 | 6 3/4 |
| 21 5/8 | 6 7/8 |
| 22 1/4 | 7 |
| 22 1/2 | 7 1/8 |
| 23 | 7 1/4 |
| 23 3/8 | 7 3/8 |
| 23 3/4 | 7 1/2 |
| 24 | 7 5/8 |
| 24 1/2 | 7 3/4 |
| 25 | 7 7/8 |
| 25 1/4 | 8 |