The following measurements are the dimensions of the actual product, not of the pet they fit. After measuring your pet, make sure all measurements fit within the following dimensions (with a little room to spare in the chest and neck).
| Back Length | Chest (Most Important) | Neck | Weight |
| X-Small | 8" | 12" | 9" | 3 - 5 lbs. |
| Small | 10" | 15" | 12" | 6 - 10 lbs. |
Medium
| 12" | 19" | 14" | 11 - 16 lbs |
Large
| 16" | 22" | 18" | 16 - 25 lbs. |
| X-Large | 22" | 26" | 20" | 26 - 45 lbs. |
| XX-Large | 26" | 32" | 22" | 45 - 60 lbs. |
| XXX-Large | 32" | 36" | 24" | 60 - 75 lbs. |
