While shopping for a Pet Door, you may notice that many manufacturers use a pet's weight as the principle guideline for determining what size pet door you need. While the weight of your pet is one of the factors to consider, you should not purchase a pet door solely based on your pet's weight. The most important factor to consider when sizing your pet for a pet door is the overall stature of your pet (shoulder height and width). So before you purchase a pet door please review the following guidelines. Doing so will ensure that you pick the appropriate size pet door for your pet.

First you will need to physically measure your largest and smallest pets. Doing this is as simple as using a yard stick, or tape measure, and taking a measurement of your pet standing on all fours. You will need to measure from the floor to the top of the shoulder/bottom of the neck. (What is considered the withers of a horse).  Once you have this measurement, the following considerations should be taken into account. See the diagrams below for examples.

• Pet Door Height - It is important that the top of the pet door opening be positioned at least 2" above the shoulder of your tallest pet. This allows your pet to move through the pet door without crouch or hunching down. The crouching motion can actually become very discomforting to pets as they age and develope hip and joint arthritis. While some dogs might be able to maneuver through smaller, tighter openings, as they age, this may not always be the case. Also, properly positioning the pet door 2" or more above your tallest pets shoulders will extend the life of the pet door flaps, saving you money. If your pet door is positioned too low, the flaps will pinch at the top, causing them to wear our early. 

• Pet Door Width - Determining how wide an opening your pet needs in a pet door is quite easy. Simply open a door in your home partially, measuring the width of the opening you create. Then old the door at that width you just measured and call your pet through the door. If you pet moves through the opening without any trouble, it is likely a suitable opening width size. If it is tight, you will need to go with a wider pet door. Typically pets do not need a lot of extra room in terms of the width. However, it is important to leave a little room on either side to minimize wear and tear on the pet door, and to leave room for your pet to grow.

• Pet Door Rise - The Pet Door Rise is the distance from the ground to the bottom of the pet door. Determining the appropriate rise depends on several factors. If you have multiple pets, you need to be sure that you position your pet door low enough to the ground that the smallest pet can get through the opening easily. If you have only larger pets, the rise can likely be a bit higher, but you have to consider the possiblity of mobility issues as your pets age. As a general guideline is is important to make sure you position your pet door with a minimum of a 2" rise. Positioning the pet door 2" up from the floor ensures that you will preserve the integrity of your mounting surface.

Special Consideration for Wall Mounted Pet Doors - When sizing for wall mounted pet doors it is important to pay special attention to the height of the inside tunnel. Smaller pets, or pets with mobility issues will most times step inside the tunnel before stepping all the way through. If you believe your pet will need to step in the tunnel to pass through the wall mounted pet door you will need to allow for enough clearance in the tunnel for your pets shoulder height. 

Example Diagrams of How to Size Your Pet for a Pet Door