Short Answer

Measure your pet’s width, height, and step-over height, then add 50 mm (2 inches) for clearance. For Patio Pet Doors, the total height needed is calculated by adding height + step-over height, while standard pet doors only require height since there is no step-over. 

Why Measuring Matters

Choosing the right size pet door ensures your pet can move through comfortably and safely.

There are two different ways to measure, depending on the type of pet door:

• Patio Pet Door (insert in sliding door)

• Standard Pet Door (cut into a door or wall)

The key difference is how you measure your pet’s height.

Method 1: Measuring for a Patio Pet Door

Use this method for Glass Patio Pet Doors and other sliding door inserts.

1. Measure Width

Measure the widest part of your pet (usually across the chest)

Add 50 mm (2 inches) for clearance

2. Measure Height

Measure from the bottom of your pet’s chest or belly to the top of their shoulders (the tallest point)

Add 50 mm (2 inches)

This ensures your pet can pass through the opening comfortably without crouching.

3. Measure Step-Over Height

Measure from the floor to the lowest part of your pet’s chest or belly

This is your pet’s step-over height (how high they need to step to enter the door).

 How to Work Out Total Height Needed 

To estimate the total height your pet needs:

• Height + Step-Over Height = Required Opening Height

This is especially important for Patio Pet Doors, where the frame sits above the ground and creates a step-over.

Method 2: Measuring for a Standard Pet Door

Use this method for doors installed into timber doors, walls, or screens.

1. Measure Width

• Measure the widest part of your pet

• Add 50 mm (2 inches)

2. Measure Height

• Measure from the bottom of your pet’s chest or belly to the top of their shoulders (the tallest point)

  Add 50 mm (2 inches)

This works because standard pet doors are installed lower and don’t require stepping over a frame.

Key Difference Between the Two Methods

Important Considerations

• Always add 50 mm (2 inches) to all measurements for comfort

• If you have multiple pets, measure the largest pet

• Ensure the step-over height is not too high for smaller or older pets

Because every home and installation is different, customers should always measure their pet and installation area before choosing a pet door.

Helpful Tip

If your pet is still growing, choose a slightly larger size to avoid needing to upgrade later.

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