If you have a big dog, or a household with multiple large breeds, choosing the right extra large dog door is one of the most important steps in giving them safe, comfortable access to the outdoors. Oversized breeds need more space to pass through easily, and the wrong fit can lead to hesitation, discomfort, or even injury.
Whether you're installing your doggy door in a patio, wall, or door surface, learning how to measure correctly ensures your pet enjoys freedom without straining, ducking, or squeezing. Below, we’ll walk you through the exact steps to size an extra large doggie door and avoid common mistakes.
Why Proper Measurement Matters for Large Dogs
Larger dogs have taller shoulders, broader chests, and take bigger steps than smaller breeds. That means the average flappy pet door won’t cut it. A properly sized opening:
- Prevents joint strain, especially for aging large-breed dogs
- Allows confident, natural movement
- Reduces wear on joints and back muscles
- Ensures long-term comfort and independence
- Prevents damage to the door and door frame from squeezing or pawing
If you’ve ever seen your dog duck, hop, or wiggle awkwardly through a small opening, it’s time to upgrade.
Step-by-Step Guide: Measuring for an Extra Large Dog Door
To measure your extra large dog door, follow these simple steps:
1. Measure Your Dog’s Height
Stand your dog on a flat surface and measure from the floor to the top of their shoulders.
This number determines how tall the door opening needs to be.
Pro Tip: Add at least 2 inches to this height so your pet doesn’t have to crouch.
2. Measure Your Dog’s Width
Measure across your dog’s widest point — typically the chest or hips.
Then add 2 inches to this width to prevent rubbing and allow smooth entry and exit.
For big breeds like Great Danes, Mastiffs, German Shepherds, and Rottweilers, width is just as important as height.
3. Measure Belly Clearance
Some large dogs have deep chests but slim hips, meaning they hang lower when walking.
Measure from the lowest point of the stomach to the floor.
The bottom of the extra large doggie door should sit just 1–2 inches below this point for comfortable stepping.
Avoid installing the flap too low. This causes drafts and makes installation difficult.
4. Factor in Your Pet's Age & Future Mobility
Big dogs age quickly, and joints naturally weaken.
If your dog is still young, ensure the dog flap XL size allows extra room so they won’t struggle later in life.
It’s better to size slightly bigger now than replace the door later.
Common Mistakes to Avoid
- Guessing door size instead of measuring
- Forgetting to add extra inches for comfort
- Installing too high (makes your dog jump)
- Installing too low (causes air leaks + strain)
- Choosing low-quality doors with cheap materials that flex, break, or warp
Remember: large dogs need sturdy frames, thick flaps, or better yet, motorized doors for safe long-term use. High Tech Pet's complete line of pet doors, including the Large Wifi Controlled Power Pet Door, the Armor Flex Dog Door, and the Duraflex Heavy Duty Dog Door check all of the boxes above and are perfect for dogs that weigh 100 lbs or even more.
When to Choose an Electronic Extra Large Dog Door
For big breeds, electronic and motorized doors are ideal because they:
- Don't have flaps that sway in strong winds
- Provide secure access only for your pet
- Offer smoother, quieter entry
- Reduce strain on dogs compared to pushing heavy flaps
High-end extra large dog door models (like High Tech Pet Power Pet doors) glide open automatically, making them perfect for heavy, senior, or mobility-restricted large dogs.
Installation Tips for XL Pet Doors
- Ensure secure mounting hardware; large cutout holes need support
- Seal edges for weather protection (High Tech Pet's doors come with weather strips)
- Consider the height you need - your first choice may be a wall or a patio install for a tall door, but High Tech Pet's new Power Pet Roll-Up Door has a new design that saves vertical space, and even the larger models can fit under windows in doors.
- Use a ramp if your dog has arthritis or hip dysplasia
For dog flap XL installations in walls, choose brands specifically engineered for wall-mount durability. The DuraFlex and Armor Flex Doors by High Tech Pet are great options.
How to Tell You Picked the Right Size Door for Your Extra Large Dog
- Your dog walks through with head upright and without any body parts rubbing rhe edges
- Dog enters smoothly; no jump or crouch
- Door seals firmly behind your dog. You shouldn't have to touch the flap oir panel at all. As a matter of fact, you should be completely relieved of doggy doorman duty!
Comfort is key. Big dogs deserve easy access too.
Final Thoughts
Choosing and installing the right extra large dog door is about more than freedom for your pet, convenience for you, and safety for your home. It's about protecting your dog’s health and mobility. With correct measurements and a quality model designed for large breeds, your pet will enjoy safe, dignified freedom every day.
Whether you're upgrading for a giant-breed puppy or making life easier for a senior big dog, measuring properly ensures long-lasting comfort and performance.
Ready to choose the perfect extra large doggie door? Explore High Tech Pet’s premium, motorized or dog flap XL systems at HighTechPet.com, built strong, sealed tight, and perfectly sized for the biggest best friends.
