cat using a correctly sized cat flap
Choosing the correct cat flap size is an important part of any installation. A flap that is too small can make it uncomfortable for your pet to pass through, while an unnecessarily large opening may not be suitable for your door, glass or chosen installation location.
With so many cat flap models available, it can be difficult to know which size is right for your pet.
This guide explains how to choose the correct cat flap size and what to consider before ordering a new installation.
Table of Contents
- Why Cat Flap Size Matters
- How to Measure Your Cat
- Measuring Your Cat’s Height
- Measuring Your Cat’s Width
- Should You Choose a Larger Cat Flap?
- Cat Flap Dimensions vs Opening Size
- Choosing a Cat Flap for Glass
- What If Your Cat Is Still Growing?
- Common Sizing Mistakes
- Final Thoughts
- FAQs
Why Cat Flap Size Matters
Your cat should be able to pass through the flap comfortably without squeezing through the opening.
The correct size can make the flap easier and more natural for your pet to use.
When choosing a cat flap, consider both:
- The size of your pet
- The manufacturer’s recommended opening dimensions
Do not rely only on the overall external size of the cat flap. The actual opening your cat passes through is usually smaller.
How to Measure Your Cat
Before buying a cat flap, take a few simple measurements.
You will need to consider your cat’s:
- Height
- Width
- Body size
- Age
- Expected adult size
Your cat should have enough room to move through the opening comfortably.
Measuring Your Cat’s Height
Measure from the floor to approximately the top of your cat’s body.
This can help determine the appropriate height at which the cat flap should be positioned.
The flap does not need to be installed at the full height of your cat, but the opening should be positioned comfortably for your pet.
A professional installer can help determine the most suitable position.
Measuring Your Cat’s Width
Measure the widest part of your cat’s body.
This is particularly important for larger or heavier cats.
The cat flap opening should provide enough clearance for your pet to pass through without becoming stuck or uncomfortable.
Always compare your measurements with the manufacturer’s internal opening dimensions.
Should You Choose a Larger Cat Flap?
A larger cat flap is not automatically better.
Choosing a model that is significantly larger than necessary may:
- Require a larger opening
- Affect the appearance of the installation
- Require more space
- Not be suitable for some glazing configurations
The best approach is to choose a flap that comfortably accommodates your pet while remaining appropriate for the installation surface.
Cat Flap Dimensions vs Opening Size
One of the most common mistakes is looking only at the external dimensions of the cat flap.
Manufacturers may provide several measurements, including:
- Overall frame size
- Tunnel dimensions
- Internal opening
- Required cut-out size
- Door or panel thickness
These measurements are not always the same.
This distinction becomes particularly important when installing a cat flap into glass.
The replacement glass needs to be manufactured according to the required opening and installation specifications.
Choosing a Cat Flap for Glass
If you are installing a cat flap into double glazing, the correct model should be selected before the replacement glass is ordered.
The installer needs to know the required opening dimensions so that the new sealed glass unit can be manufactured correctly.
Changing the cat flap after the glass has been manufactured may mean that the opening is no longer suitable.
For this reason, confirm the exact cat flap model and dimensions before placing an order for bespoke replacement glass.
What If Your Cat Is Still Growing?
Kittens can grow significantly during their first year.
If your cat is still young, consider its expected adult size when selecting a cat flap.
However, choosing an excessively large flap for a small kitten may not be ideal.
The most suitable option depends on the cat’s expected size, the flap design and the manufacturer’s recommendations.
Common Sizing Mistakes
Several mistakes can make cat flap installation more difficult.
Choosing Based Only on External Dimensions
Always check the actual opening size.
Forgetting the Door or Glass Thickness
Different cat flaps have different fitting requirements.
Ordering Glass Before Selecting the Flap
The glass opening needs to match the chosen cat flap.
Positioning the Flap Too High
Your cat should be able to use the flap comfortably.
Not Considering Future Growth
Young cats may need a larger model as they mature.
Final Thoughts
Choosing the correct cat flap size helps ensure your pet can use the installation comfortably and safely.
Before ordering, measure your cat and check the manufacturer’s internal opening and cut-out requirements rather than relying only on the overall dimensions.
For glass installations, selecting the cat flap before the bespoke replacement unit is manufactured is particularly important.
Accurate measurements and professional installation can help ensure the finished cat flap provides reliable access while maintaining a neat appearance.
FAQs
How do I know what size cat flap my cat needs?
Measure your cat’s body width and height, then compare these measurements with the manufacturer’s recommended opening size.
Should a cat flap be bigger than my cat?
It should provide enough clearance for comfortable use, but there is usually no need to choose a significantly oversized model.
Does the cat flap frame size matter?
Yes, but the internal opening and required cut-out dimensions are particularly important when planning an installation.
What size cat flap is suitable for a large cat?
The correct size depends on the individual cat. Measure your pet and compare the measurements with the manufacturer’s specifications.
Does cat flap size matter when installing into glass?
Yes. The replacement glass opening needs to be manufactured according to the selected cat flap’s requirements, so the model should be confirmed before the glass is ordered.
