Dog Flaps UK 2026: Best Dog Flaps for Doors & Glass (and Fitting Costs)
Quick Answer: Best Dog Flaps in the UK
• Best for small dogs: PetSafe Staywell small dog flap — sturdy, lockable, suits terriers and dachshunds.
• Best for medium dogs: PetSafe Staywell medium dog flap — the popular all-rounder.
• Best for large dogs: large dog flap — for Labradors and similar.
• Best smart dog flap: SureFlap Microchip Pet Door — reads your dog's microchip, lets only your pets in. Suits small and medium dogs.
• Best for glass doors: any of the above fitted into a new toughened glass panel — get a quote.
How to Measure Your Dog
- Height: measure from the floor to the top of your dog's shoulders. The top of the flap opening should be about 5 cm above this.
- Width: measure the widest part (usually the chest) and add 2–3 cm.
- Step-over: the bottom of the flap should be no higher than about a third of your dog's leg height so they can step through comfortably — especially older dogs.
If your puppy will grow, size for the adult dog.
Dog Flap Sizes at a Glance
| Size | Typical dogs | Approx. opening |
|---|---|---|
| Small | Jack Russell, Dachshund, Shih Tzu | ~18 x 15 cm |
| Medium | Cocker Spaniel, Beagle, Staffie | ~23 x 20 cm |
| Large | Labrador, Retriever, Boxer | ~30 x 28 cm |
| Extra large | Very large breeds | ~35 x 45 cm+ |
Which Doors Can a Dog Flap Go In?
• uPVC doors: fitted into the lower panel. From £60 fitted.
• Wooden and composite doors: fitted into the door, depending on construction. Ask us for a price.
• Glass doors and French doors: the existing glass can't be cut, so we fit the dog flap into a new toughened glass panel. From £280 fitted.
• Sliding patio doors: fitted into a new glass panel in the same way.
We don't fit flaps into walls.
Microchip Dog Flaps
A microchip dog flap only opens for your registered pets, so neighbours' cats and foxes stay out. The SureFlap Microchip Pet Door and Pet Door Connect suit small to medium dogs. Larger dogs usually need a manual dog flap with a lock. See our best microchip cat flap guide for how microchip flaps work, and our SureFlap Pet Door troubleshooting guide if yours is playing up.
Get a Dog Flap Fitted
We fit dog flaps across Greater Manchester, Cheshire, Lancashire and Staffordshire. Tell us your door type and your dog's size and we'll give you a price: get a free quote or find a cat & dog flap fitter near you.
As an Amazon Associate we earn from qualifying purchases at no extra cost to you.
Shop Microchip Cat Flaps on Amazon:
Manual Cat Flaps:
