Click on the cat or dog wood-fitting links above to find all the information you require on the size of the pet door, and what size of pet it suits. It will also show whether you require a slimline version which suits thinner substrates from 11mm to 30mm or a tunnel version which suits 11mm to 50mm. An added advantage of the tunnel version is the tunnel does not need to be cut, it simply closes up to the substrate thickness you are installing the pet door into.
Click on the cat or dog glass-fitting links above to find slimline versions and dual-glaze versions depending on whether you want your pet door for single or double glazing. As you will require a glass company or glazier to prepare the glass for you, they can confirm what pet door you require.
Choosing the right cat flap or dog flap size is important for your pet’s comfort, safety, and ease of use. A flap that is too small can make your pet uncomfortable, while a flap that is too large may reduce weather resistance and security.
Below is an easy-to-understand size guide showing common pet types and the recommended flap opening sizes.
| Pet Type | Typical Weight Range | Recommended Flap Opening | Best Flap Type |
|---|---|---|---|
| Kittens | Under 3kg | Small | Cat flap |
| Average Domestic Cats | 3kg – 6kg | Small to Medium | Cat flap |
| Large Cats (Maine Coon, Ragdoll etc.) | 6kg – 10kg | Medium | Large cat flap |
| Small Dogs (Chihuahua, Toy Poodle) | Under 5kg | Small to Medium | Small dog flap |
| Medium Dogs (Cocker Spaniel, Beagle) | 5kg – 15kg | Medium | Dog flap |
| Large Dogs (Labrador, Golden Retriever) | 15kg – 35kg | Large | Large dog flap |
| Extra Large Dogs | 35kg+ | Extra Large | Heavy duty dog flap |
How to Measure Your Pet for a Cat Flap or Dog Flap
To select the correct pet flap size:
1. Measure Your Pet’s Width
Measure the widest part of your pet, usually across the shoulders or chest.
2. Measure Your Pet’s Height
Measure from the floor to the top of your pet’s shoulders.
3. Add Clearance Space
Allow a little extra room so your pet can comfortably pass through the flap without squeezing.
Important Tip for Glass Installed Cat Flaps & Dog Flaps
If installing into glass, especially double glazed or toughened glass, the hole size must match the pet flap model exactly.
Always check the technical specifications for your selected model before ordering replacement glass.
For double glazed units, the glass must normally be manufactured with the hole pre-cut before toughening.
Recommended Pet-Tek Cat Flap & Dog Flap Models
Choose a Cat Door If:
Recommended models: For Glass
Choose a Dog Door If:
Recommended model: For Glass
