| Size | Neck girth | Chest girth | Typical weight |
|---|
| S | 10–14 in | 16–22 in | 10–25 lb |
| M | 14–18 in | 22–28 in | 25–55 lb |
| L | 18–24 in | 28–36 in | 55–90 lb |
How to measure: neck = where the collar naturally sits, leaving room for two fingers · chest = widest point behind the front legs. Between sizes? Size up.
