Measure around the widest part of the chest, just behind the front legs. Between sizes, size up.
| Size | Chest (in) | Back (in) | Usually fits |
|---|---|---|---|
| XS | 12 to 14 | 8 | Chihuahua, Yorkie |
| S | 14 to 17 | 10 | Maltese, Toy Poodle |
| M | 17 to 20 | 12 | Shih Tzu, Cavalier |
| L | 20 to 23 | 14 | Frenchie, Pug, Dachshund |
| XL | 23 to 26 | 16 | Corgi, Beagle |