Measuring your pet for a pet door is quite simple. Follow the simple instructions below to accurately measure your pet in order to choose the right size for your pet.

If at any point you are uncertain about your measurements, feel free to reach out to us at or at (888) 557-7387.

Measuring Your Pet

  1. Measure the Height

    Measuring the height of your pet is simple. The height will be used to determine how high you can install the pet door. Grab a tape measure and measure from the ground to the tallest point of your pet’s back. We suggest adding an inch or two to this measurement just to be safe.

    The top of the flap should be at least 1" above the top of the dog's back

  2. Measure the width of your pet

    The width will be used to determine the width of the flap that you will purchase. All you need to do is open a door wide enough so that your pet can walk through comfortably. Once your pet walks through, measure that width of the opening and add an inch or two for safety.

    Measure how wide of an opening your pet can fit through, don't measure the pet directly
  3. Measuring the Step-Over / Rise

    The step over or “rise” is the measurement from the bottom of your door or wall to the base of the pet door. This is basically the height that your pet must step over in order to get through the door. Please note that this measurement should be factored in with the pet’s height you measured earlier when choosing an appropriate pet door height. With step overs, the lower they are, the easier it is for the pet to get through. For dogs with health issues such as arthritis or are of old age, it is recommended that you have a small step over.

    Make sure your pet can comfortably step over the distance between the pet door and the ground

To summarize, here is a diagram of the measurements you should take:

Flap height + step over = total height. The total height should be at least 1" taller than the top of the pet's back

Measuring Your Door or Walls

Besides measuring your pet, you also have to measure your door or wall when installing a pet door. There are two measurements you must take into consideration: the rough opening size and the outer frame size. The rough opening size is the actual size of the hole that you will be cutting into your door or wall. Generally the inner frame of the pet door will fit in there. The outer frame measurement is the measurement of the outer framing of the pet door that’s usually a couple inches larger. For tight spaces, this outer frame measurement is important to know.

Outside frame dimension and rough opening measurement

Measuring for a Sliding Glass Door Pet Door

Measuring your sliding glass door is a must before purchasing a sliding glass door panel pet door. There generally isn’t a standard height for sliding glass doors and they can vary greatly from brand to brand.

Here’s how to measure:

Place the end of the measuring tape you use up inside the track as high as it will go and measure down a convenient distance and then draw a line with a pencil.

Then, put the end of the measuring tape down into the track towards the bottom and start measuring from the line you drew previously.

Simply add those two numbers together and you got your track height.

If you measure all at once, you might not get the most accurate number as the measuring tape curves towards the bottom. The different sizing ranges for panels is precise and if you happen to mis-measure, it will become a hassle.

Other Things to Consider When Choosing the Correct Size Pet Door

If you currently have a puppy or kitten, remember that they will continue to grow. Finding out the size that they will be approximately can help you make the right purchase. People often judge this based on their parents’ size.

Having a door that is mounted low gives more comfort for pets to step over. Young pets should have no problem going through a door, but as they age, having a higher step over can become an issue for pets with health issues.

Making sure the pet door is tall enough for your pet is also crucial with age as having a pet door that is too short will require hunching from your pet, which over time can be hard on your pet’s hips. Flaps will generally last longer too if the pet isn’t rubbing against the top part of the door as well.

If you have multiple pets, make sure that the door you get can accommodate all of them. It must be low enough for the shortest pet to step over but also tall enough for the tallest one to fit through comfortably.

Got any questions on measuring? We're here to help. Call us at (888) 557-PETS or send us an email at 


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