How to Measure for Your New Pet Door

What size dog door do I need? No matter where your pet door is going, the first thing you need to do is take your pet's measurements. Wondering how to measure a dog's height?

border collie and brown lab lying next to each other

If you ask our pet door experts they'll tell you to measure your pet from the ground to the top of their shoulders using this measurement guide. This will help give you an idea about which door sizes will or will not work for them. Once you know how to measure dog height you can start looking for flaps that will accomodate their size. Knowing how to measure height of dog ensure that you set your furry friend up with the perfect door for them. Follow this guide to measure your pet for the perfect pet door.

The specific measurements of your pet are crucial when choosing a door. Basing your selection on average breed weight poses the risk that you will buy the wrong door size. Why is this? Think of it like this: you can have a short and wide bulldog and a tall and skinny poodle weigh exactly the same, yet measure completely differently in terms of height and width. Here are some tips on how to measure your dog for proper doggie door sizing:

1. Measure height of dog from the floor to the top of their shoulders.

2. Determine the step-over distance your pet(s) is comfortable with.

3. Open a regular people door that is wide enough for them to get through, and measure that door opening width.

4. Search for pet doors in your desired install location (in a door, in a wall, for sliding glass doors... etc.).

5. Select pet door options based on your pet’s required flap size.

Measure their Height

Take their height from the floor to the top of your pet's shoulders. Think: shopping for shoes! At the store, we tend to walk straight to our size section, then pick a pair we like. Then, we try a shoe on to make sure we have enough wiggle room and can walk comfortably.

Getting Over and Out with One Pet or More

Our pet door experts will also ask you about "step-over" height. This is the space between the bottom of the pet door opening and the actual floor. 

In the same way stepping over hurdles gets more challenging the bigger they are, a step-over can have the same effect on your pet. So if you have pets of varying sizes the question turns from what size door for my dog to what size flap for my dog and cat.

Keep in mind that cat door dimensions are generally much smaller than dog doors, so cats might have a hard time pushing through large dog flaps. With an extra large dog door you want to keep the step-over as low as possible for your cat, and keep (at least) an inch of space at the top for your dog. A low step-over also allows pets to continue using the pet door as they grow older.

So, the proper height for a flap has to consider a pet’s height, width, and ‘step over’ range. Generally, the bigger the flap size, the lower you can insert your frame. The smaller the flap size, the higher you would need to install the pet door. Granted, this is if you have done your measurements correctly to ensure your pets will not scrape their backs.

dog door sizes: how to measure dog height to choose the right one

Quick Tip 

Unlike shoe shopping, we can't really have our pet's try out a door for size. To "test out" if a door will be the right size, you can use a cardboard cutout to resemble a flap opening. Have your pet walk through it and check if they have enough room.

For shoes, we check for wiggle room so our feet don’t get hurt. Similarly, you will want to make sure the top of the flap is at least one inch from your pet’s shoulder. Using the cardboard, you also want to make sure the opening is wide enough for a smooth pass. It is not recommended to measure your pet’s width directly.

Instead, give him/her enough room on either side in case they grow more! If you don’t check for wiggle room, your pup might end up in a tight squeeze! If the door is too low, they might scrape their back.

So...What size door do I need? Let's run through an example On 

“Do you know your pet’s height from feet to shoulder?”

Yes, 14 inches from feet to shoulder!

“Great, do you know how high off the ground you plan on installing the door?”

Well, I am thinking about 3 inches from the ground. My dog’s legs are not that tall! answer: You want to make sure the top of the flap is one inch from your pet's shoulder. So to be sure that happens, you should choose a flap size that is 12 inches high at the minimum. Since you’re raising the door 3 inches from the ground, the top of a 12 inch flap will end up 15 inches from the ground. That gives your pet the one inch space at the shoulder. Make sure to check the width on any flap too!

Measuring before purchase matters. With any job requiring measurements, it’s always better to be safe than sorry. How does the expression go – measure twice, cut once? We’ve heard customers over the past 30 years and their stories about cutting the wrong size hole because of a incorrect measurement, and we feel like it is our job to help inform all of our customers and potential customers on the correct way to install our pet doors.

Getting the wrong size door and returning it takes time you may not have. Check with a representative for any help with flap measurements! Or, visit our video guide for a step-by-step measuring guide.

Following the How to Measure Your Pet guide will ensure that you not only install the pet door correctly the first time, but also that you have the correct size pet door for your dog or cat!

If you are measuring for a new door for your new pup, take a look at our tips on bringing a new dog home!


Cynthia Herrera

Written by

Cynthia Herrera

The Team is dedicated to providing the highest quality pet doors. As dog and cat lovers ourselves, we aim to write about the topics that matter the most to you and your furry friend. If you have any questions, please contact our customer service team. 🐶🐱

The Team is dedicated to providing the highest quality pet doors. As dog and cat lovers ourselves, we aim to write about the topics that matter the most to you and your furry friend. If you have any questions, please contact our customer service team. 🐶🐱

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