To get the most accurate size harness for your pet, measure the girth of their chest, around the widest part of your dog's torso right behind the front legs, with a cloth tape measure. Pull the cloth tape snug, but not tight. If you don't have a cloth tape measure, you can use a piece of string and measure it with a rigid ruler afterwards. Make sure there's enough room for about two fingers between the harness and your pet's chest for comfort.
| Size || Chest Girth || Neck Size || Recommended Pet Weight |
| Small || 19 to 25 inches || 15 to 21 inches || 15 to 35 pounds |
| Medium || 24 to 34 inches || 18 to 28 inches || 35 to 70 pounds |
| Large || 26 to 39 inches || 25 to 39 inches || 70 pounds and up |