O'Neills Mens Replica Jerseys Size Guide
| Size | Chest (inches) | Chest (cm) |
| S | 39-40 | 99-101.5 |
| M | 41-42 | 103-105.5 |
| L | 43-44 | 107-109.5 |
| XL | 44-45 | 111-113.5 |
| 2XL | 45-46 | 115-117.5 |
| 3XL | 46-47 | 119-121.5 |
| 4XL | 48-49 | 123-125.5 |
| Size | Chest (inches) | Chest (cm) |
| S | 39-40 | 99-101.5 |
| M | 41-42 | 103-105.5 |
| L | 43-44 | 107-109.5 |
| XL | 44-45 | 111-113.5 |
| 2XL | 45-46 | 115-117.5 |
| 3XL | 46-47 | 119-121.5 |
| 4XL | 48-49 | 123-125.5 |