When trying to decide between two sizes, choose the larger size for a better fit.
| Size | Chest* | Neck* | Breed Examples |
| Extra Small | 12 | 7 | Teacup and Puppies under 5 lbs |
| Small | 14 | 11 | Chihuahua, Pomeranian, Australian Terrier, Yorkshire Terrier, Toy Poodle |
| Medium | 17 | 25 | Pug, Maltese, Jack Russeli Terrier, French Bulldog, Boston Terrier |
| Large | 20 | 22 | Bichon Frise, Beagle, Cocker Spaniel, Corgi, Scottish Terrier |
| Extra Large | 24 | 28 | Springer Spaniel, Brittany Spaniel, Collie, Bulldog, Schnauzer |
| 2X Large | 32 | 36 | Doberman Pinscher, Golden Retriever, Labrador Retriever, Pit Bull |
| * in inches |
