Choosing the right pet door starts with one simple but critical step: accurate measurement. Even the highest-quality pet door won’t perform properly if it’s too small, too large, or installed at the wrong height.

At Moore Pet Supplies, we’ve spent 30 years helping pet owners get this step right the first time. Proper sizing ensures comfort for your dog, better energy efficiency for your home, and long-term performance from your pet door.

Here’s exactly how to measure your dog for the perfect fit.

Step 1: Measure Your Dog’s Height
Have your dog stand naturally on a flat surface. Measure from the floor to the top of their shoulders (also called the withers). This is the most important measurement.

The top of the pet door flap should be at least 1–2 inches taller than your dog’s shoulder height to allow comfortable passage without crouching.

Step 2: Measure Your Dog’s Width
Next, measure the widest part of your dog—usually across the chest or hips. The flap opening should be slightly wider than this measurement to allow easy movement without squeezing.

Step 3: Consider Growth (If You Have a Puppy)
If you’re installing a pet door for a growing puppy, factor in their projected adult size. It’s better to size appropriately for their full-grown height rather than replacing the door later.

If you have multiple dogs, always measure the largest one and size accordingly.

Step 4: Check Step-Over Height
Step-over height refers to the distance from the floor to the bottom of the pet door opening. This should sit low enough for your dog to step through comfortably.

For older dogs or smaller breeds, keeping the step-over height minimal is especially important for ease of use.

Step 5: Think About Energy Efficiency
A door that’s significantly larger than necessary can reduce insulation performance. Choosing a properly sized, well-sealed pet door helps maintain your home’s comfort year-round.

Precision matters—not just for comfort, but for efficiency too.

Why Proper Measurement Makes All the Difference
When sized correctly, a pet door becomes a seamless part of your home. Your dog moves freely, your home stays comfortable, and you avoid the frustration of returns or replacements.

Incorrect sizing, on the other hand, can lead to hesitation from your pet, drafts, or long-term dissatisfaction.

For three decades, Moore Pet Supplies has helped customers nationwide find the right fit the first time. That’s part of why we continue to be recognized as America’s #1 Choice for Pet Doors.

If you’re unsure about sizing, taking a few extra minutes to measure carefully can make all the difference. The right fit ensures comfort, convenience, and confidence—for both you and your dog.