'In Glass' Pet Door Size Determination for your Pet

Pet door opening suggestions for size and step-over

Sizing The chart below lists pet door opening sizes for the Endura Flap™ pet door by Patio Pacific. The combination of 'step-over' plus the pet opening height you select should total 1" or more above the tallest pets back.

  • First, measure your tallest pet from the floor to the top of the shoulder (base of the neck). Record the number. Determine the pet door size best suited for you and your pets needs.
  • Next, establish "your doors" minimum step-over. This is the minimum step-over height for your door after install.
    First, locate the bottom of your existing glass.This will be approximately 3/4" below the top of the bottom framing.
  • Measure from the floor to the bottom of the glass. Record the number. Add 3 3/4" for the Endura Flap™ framing.
  • The total equals your doors minimum step-over height after installation. Most trim line vinyl and aluminum doors will have between 5"-8" of minimum step-over depending on bottom rail thickness and the pet door you select. French rail doors and swing doors with kick panels will be higher.
  • Review the After Installation page to find the ideal combination of step-over, pet opening size and height for your application. We can add step-over if needed. Review the adding additional step-over page. We can add an insulated spacer between the frame and pet door to raise the door up for taller pets' ease of use.

How high should the pet opening be?

You will want the top of the pet opening to be approximately 1" above the high point of the tallest pet's back. This will be the most accessible for your pet. Example: a #08 Endura Flap™ pet door with a step-over  of 6" added to the opening height of 15" will total approximately 21". This combination will work well for pets with a maximum shoulder height of 20".

How low to the floor should the pet opening be?

If you have several pets, it should accommodate the smallest pet's ability to see through. With larger pets, keep in mind an appropriate step-over that will allow for ease of use now as well as in the future as they grow older and slow down with age. As noted above, step-overplus opening height should total 1" above the tallest pets back.

How big should the opening be?

The pet opening should allow your pet to pass through comfortably. The chart below shows opening flap dimensions. If in doubt, create a cardboard opening for your pet to step through using the opening sizes noted below.

Pet Door Opening Sizes

SizeEndura Flap™ by Patio Pacific
Small #066" w x 11" h
Medium #088" w x 15" h
Large #1010" w x 19" h
Extra Large  #1212" w x 23" h