Pet Door Sizes

We offer ten door sizes to fit all dogs and cats,
from chihuahuas to great Danes!

Choose the right door size for your pet.

Keep in mind that when your pet is young and agile, it can easily maneuver through a small opening. As pets get older, dogs in particular can get arthritis in the back legs and hips. A Solo pet door lasts for more than 15 years, so as your pet ages, a slightly larger pet door with more headroom and installed lower to the ground will make it easier for your dog to enter and exit.

First, measure your pet’s width. Use a tape measure to determine the widest part of its body (typically the shoulders just below the neck). In some dogs the hips are larger, so measure just above the back legs.

Second, measure your pet’s height. Start at the top of its shoulders and measure downward to the floor. Your pet can crouch, so this is just a general guideline for the height of the door.

Third, using sturdy cardboard, cut an opening that is slightly wider than your pet’s width, but shorter than its height. Place a treat on the other side and see if your dog can fit through the opening. Adjust the cardboard “door” as necessary or use a fresh one. The goal is to make the door as small as possible without making it too small for your dog to successfully and safely get in and out.

Lastly, choose a door closest in size to the cardboard door. If there is no exact match, choose one slightly larger, not smaller.


Be sure to take into consideration the overall height of the pet door frame, and not just the opening’s height. The actual height of the pet door frame is MORE THAN TWICE AS HIGH as the pet opening. For example, Model 1812 has a pet opening 18″ high, but the overall height of the door is 40″. This is crucial if you’re installing it in a wall below a window or in a human door with a window.

Be aware that each pet door frame is 4″ deep. This is important if you’re installing it in a human door.

Pet Door Sizes, including overall dimensions (not drawn to scale)

INTRUDER ALARM: When ordering a large pet door, please consider our optional Intruder Alarm, due to the increased possibility of unwanted entry. It can only be ordered from the Order Pet Door page at the time of purchase.