Richard James x Castore Trouser Size Guide
| Castore Size | Waist (In) | Waist (cm) | Hip (In) | Hip (cm) |
| XS | 28-30 | 71-76 | 32-34 | 81-86 |
| S | 30-32 | 76-81 | 34-36 | 86-91 |
| M | 32-34 | 81-86 | 36-38 | 91-96 |
| L | 34-36 | 86-91 | 38-40 | 96-101 |
| XL | 36-38 | 91-96 | 40-42 | 101-106 |
| XXL | 38-40 | 96-101 | 42-44 | 106-111 |
| XXXL | 40-42 | 101-106 | 44-46 | 111-116 |