How to Pick the Correct Sized Dog Door

by Victoria Lee Blackstone
    The right dog door will depend on the size and ability of your dog.

    The right dog door will depend on the size and ability of your dog.

    Brand X Pictures/Brand X Pictures/Getty Images

    A dog door offers your pooch the freedom to go in and out when he chooses. Picking the correct sized dog door before installation enables your dog to make it through the door safely. In addition, the right size door for your dog increases the longevity of the door. When choosing the correct size, there are a couple things to consider.

    Step 1

    Measure your dog’s width with the tape measure. Take this measurement across the widest part of your dog’s chest. Add an additional 2 inches to this measurement to ensure your dog will be able to pass through the door safely. This measurement will be the minimum width of your dog door.

    Step 2

    Measure your dog’s height from the top of his back to the lowest part of his chest, usually right behind the front legs. Add an additional 2 inches to this measurement. This is the recommended height of the dog door.

    Step 3

    Cut an opening with these measurements in a large piece of cardboard. Encourage your dog, with a treat, to step through the cardboard. Watch how your dog moves through the opening. If he has difficulty, add additional inches as needed.

    Step 4

    Consider the rise of the dog door when choosing a particular type. The rise refers to the height the door will be above the ground when installed. For short-legged dogs or dogs suffering with arthritis, lifting their legs may be difficult. While the opening measurement of a door is important, the rise height is also a factor.

    Items You Will Need

    • Tape measure
    • Large piece of cardboard
    • Scissors
    • Dog treat


    • When choosing a dog door for a puppy, use the parent’s measurements, if possible. If not, ask your veterinarian to estimate your puppy’s adult size.
    • When performing the cardboard test, look for the clearance above your dog’s back when he passes through. To extend the life of the door flap by reducing stress on the flap connections, you want to have 1.5 to 2 inches of clearing above your dog’s back.
    • If you have multiple dogs, choose a door that meets your largest dog’s measurements. However, remember to consider the rise measurement for smaller dogs.


    • A door that is too small for your pet can lead to injuries.

    Photo Credits

    • Brand X Pictures/Brand X Pictures/Getty Images

    About the Author

    Victoria Lee Blackstone is a horticulturist who propagates heirloom and native plants for her nursery. She has authored research-based scientific/technical papers, plant care sheets and magazine and newspaper articles. Blackstone studied botany and microbiology at Clemson University and is a former University of Georgia Extension Master Gardener Coordinator.

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