PlexiDor Sizing and Measuring
How To Measure Your Pet & Choose a Pet Door
We recommend the “Cardboard Test” to ensure correct size for your pet. Using the OPENING SIZE measurement in the charts, cut a hole in a piece of cardboard, and see if your pet can pass through easily. Or wedge open a house door the OPENING WIDTH, and block off the OPENING HEIGHT (starting just above your pet’s shoulder) and call your pet through. Pets duck their heads as they push open their doggie door or cat door and step through it, so ideally you should install the dog or cat door with the top of the opening just above your pet’s shoulder. But any position will do as long as your dog or cat can open the door and get through comfortably.