The only way to accurately select the proper size pet door is by physically measuring your pet. There are two important measurements you need:
- The width of the pet door opening should be at least 1" wider than the width of your pet as measured across the shoulders.
- The height of the pet door opening should be at least 2" greater than the difference between the height of your pet measured from the floor to the top of the shoulders and the ground clearance of your pet measured from the floor to the bottom of the chest.
The end goal is to have a 1" clearance at the shoulder width, a 1" clearance at the chest/belly, and 1" clearance at the back/shoulders.
As you may not find a door with the exact size you want, you should select a size that will meet your needs and make allowances for your pet’s age, weight, agility, and future growth. If you have multiple pets, you may need to purchase a larger door where the top is set to the height of larger pet’s shoulders and the rise and bottom of the door can accommodate your shorter pets.
