Tilley Hats Size Guide
| Tilley Traditional Size | Tilley Modern Size | Head Size (cm) |
| 6 7/8 | XS | 55 |
| 7 | Small | 56 |
| 7 1/8 | Medium | 57 |
| 7 1/4 | Medium | 58 |
| 7 3/8 | Large | 59 |
| 7 1/2 | Large | 60 |
| 7 5/8 | XL | 61 |
| 7 3/4 | XL | 62 |
| 7 7/8 | XXL | 63 |
| 8 | 3XL | 64 |
| 8+ | 4XL | 66 |
| Tilley Traditional Size | Tilley Modern Size | Head Size (cm) |
| 6 7/8 | XS | 55 |
| 7 | Small | 56 |
| 7 1/8 | Medium | 57 |
| 7 1/4 | Medium | 58 |
| 7 3/8 | Large | 59 |
| 7 1/2 | Large | 60 |
| 7 5/8 | XL | 61 |
| 7 3/4 | XL | 62 |
| 7 7/8 | XXL | 63 |
| 8 | 3XL | 64 |
| 8+ | 4XL | 66 |
