To fit a cat flap onto your door mark the height of your cat s stomach on the door.
Cat door height from floor.
Measure the height and width of the cat flap and mark the dimensions on the door using the height of the cat s stomach as the center point.
7 1 8 7 1 2 width height 3 easy steps to select right size cat door 1 2 3 1.
5 1 2 5 8 small 1 25 lbs.
Measure your cat s belly to the floor.
Cut out the square hole with a jigsaw and smooth the edges of the hole with fine grit sandpaper then place the cat.
This will give you the best dog door size for your household.
Width measure the widest part of your cat the chest or hips.
Subtract the height of the dog door opening for instance 16 24 16 8 height off the interior floor for the dog door install opening.
You need a pet door that has a flap height that is at least 1 taller than your largest pet and a step over no more than 1 3rd of your smallest pet s height from the floor to their back.
Measure the height of your cat s belly from the ground to its stomach with a measuring tape.
Choose a warm day.
Add one to two inches.
This is how high up the cat door needs to be from the bottom of the hollow core door.
2 for clearance for dog s back not to hit dog door 24 height of desired dog door opening.
Now you know how high the door must be to accommodate your tall dog.
You will need to take the measurements of your largest and smaller pet.