Helpful Tip: How to Measure for Your New Pet Door

What size door should I get? If you ask our pet door experts, they’ll say “Do you know how tall your pet is from feet to shoulder?”

No matter where your pet door is going, the first thing to do is size up your pup! This will help give you an idea on what flap sizes can and can’t fit your pet.

Rather than figure out what size to get for their breed or weight, the best way is with proper size assessment. Why is that? 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 pet:

  1. Measure from feet to shoulder
  2. Determine the step over distance your pet(s) is comfortable with
  3. Open a regular people wide enough for them to get through and measure door opening width
  4. Search for doors in your desired install location
  5. Select options based on your pet’s required flap size


Take their height from feet to shoulder.

It is the same concept we use when we go shoe shopping. 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 flap and the floor.

In the same way stepping over hurdles gets harder the bigger they are, a ‘step over’ can have the same effect on your pet. So if you have a multiple size pet household the question turns from what size door for my dog to what size flap for my dog and cat.  You want to keep the step over as low as possible, and keep that inch of space at the top. A low ‘step over’ also helps for older pets, access is much easier.

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 need to install. Granted, this is if you have done your measurements correctly and ensure your pets will not scrape their back.

Learn how to decide what size pet door to get for your dog or cat!

A Tip and a Trick

There’s not many pet door stores to try flap sizes on though. To help, 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 you need?

Let’s do a example:

“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 can go for 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!


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4 thoughts on “Helpful Tip: How to Measure for Your New Pet Door

  1. Yilliang Peng

    My wife and I are thinking about installing a pet door for our little labradoodle! We are not very good at doing things ourselves and so we are thinking of hiring someone to do it for us. We cannot wait to see the smile on our puppy when he goes through the doggy door for the first time! Thanks for the advice!