Please note that size charts relate to IWS's (www.iwillsp.com) own clothing brand and are designed to fit the following body measurements. Some brands may vary from these measurements, but you can still use them as a guide.
| LENGTH (inches) | WIDTH (inches) | CHEST (inches) | |
| XS | 27 | 16 ½ | 31-34 |
| S | 28 | 18 | 34-37 |
| M | 29 | 20 | 38-41 |
| L | 30 | 22 | 42-45 |
| XL | 31 | 24 | 46-49 |
| 2XL | 32 | 26 | 50-53 |
| 3XL | 33 | 28 | 54-57 |
| 4XL | 34 | 30 | 58-61 |
| 5XL | 35 | 31 | 62-65 |
| LENGTH (cm) | WIDTH (cm) | CHEST (cm) | |
| XS | 68.6 | 42 | 78.7-86.4 |
| S | 71.1 | 45.7 | 86.4-94 |
| M | 73.7 | 50.8 | 96.5-104.1 |
| L | 76.2 | 55.9 | 106.7-114.3 |
| XL | 78.7 | 61 | 116.8-124.5 |
| 2XL | 81.3 | 66 | 127-134.6 |
| 3XL | 83.8 | 71.1 | 137.2-144.8 |
| 4XL | 86.4 | 76.2 | 147.3-155 |
| 5XL | 89 | 78.7 | 157.5-165 |
