Size Chart- T-Shirts | Thirty One x Original Favorites
| Body | Chest | Sleeve | ||
| XS | 26" | 18" | 11" | |
| S | 27" | 19.5" | 12.25" | |
| M | 28" | 20.5 | 14" | |
| L | 29" | 21.5" | 15" | |
| XL | 30" | 23" | 17" | |
| XXL | 31" | 24.5" | 18.25" |
| Body | Chest | Sleeve | ||
| XS | 26" | 18" | 11" | |
| S | 27" | 19.5" | 12.25" | |
| M | 28" | 20.5 | 14" | |
| L | 29" | 21.5" | 15" | |
| XL | 30" | 23" | 17" | |
| XXL | 31" | 24.5" | 18.25" |