Dog Car Seat Size Chart UK: Find the Right Fit by Breed and Weight
by Sami Andreson on Oct 27, 2026
Weigh your dog, then choose a seat rated at least 2 to 3kg above that weight. Next, measure your dog lying down from nose to the base of the tail and check the seat's inside length is a little longer. Most dogs under 10kg suit a small booster, 10 to 20kg a medium seat or car bed, and over 25kg a large bed, back seat extender or hammock.
Buying the wrong size is the most common reason a car seat goes back. Too small and your dog is cramped or spills over the edge. Too big and a small dog slides about on every bend. This guide gives you a simple size chart by weight, a breed by breed chart for popular UK dogs, and a car chart for seat covers, so you can buy the right size first time.
How to Measure Your Dog for a Car Seat
You need three numbers. It takes five minutes with a tape measure and your bathroom scales.
- Weight. Weigh yourself, then weigh yourself holding your dog, and take one from the other. This is the number that matters most.
- Lying length. Wait until your dog is curled up or lying on their side and measure from the nose to the base of the tail. Add a few centimetres so they can turn and settle.
- Sitting height. With your dog sitting, measure from the floor to the top of the head. Taller dogs need higher walls on a booster, or a flat bed instead.
The 2 to 3kg rule. A seat's weight limit is the most it should carry, not a target. Choose a rating a few kilos above your dog's weight so the base stays firm and your dog has room to grow or shift about.
Dog Car Seat Size Chart by Weight
Use this as your starting point. Then check the inside size on the product page against your dog's lying length.
| Your dog weighs | Best type | Rating to look for | Where to shop |
|---|---|---|---|
| Under 5kg | Console seat, small booster or carrier | Up to 5 to 8kg | Console seats |
| 5 to 9kg | Small raised booster with high sides | Up to 9 to 11kg | Small seats |
| 9 to 12kg | Large small booster or medium seat | Up to 12 to 14kg | Small or medium seats |
| 12 to 18kg | Medium seat or car bed | Up to 18 to 20kg | Medium seats |
| 18 to 25kg | Large medium seat or low car bed | Up to 26kg or more | Medium or large seats |
| Over 25kg | Large bed, back seat extender or hammock | Rated 40kg or more | Large seats |
Most raised boosters stop at around 20 to 26kg. Above that, a big dog is usually safer and more comfortable lying flat on a car bed or an extender that bridges the footwell, with a harness tether clipped on.
Size Chart by Breed
Weights below are typical adult ranges for popular UK breeds. Dogs vary a lot, especially crossbreeds and working lines, so always weigh your own dog before you order.
| Breed | Typical adult weight | Seat size | Shop the breed |
|---|---|---|---|
| Chihuahua | About 2 to 3kg | Console seat or small booster | Chihuahua range |
| Miniature Dachshund | About 4.5 to 5kg | Small booster with a long base | Dachshund range |
| Standard Dachshund | About 9 to 12kg | Seat rated 12kg+ or extender | Dachshund range |
| Cavapoo | About 4 to 10kg | Small to medium booster | Cavapoo range |
| Cockapoo (miniature) | About 6 to 8kg | Booster rated 11 to 12kg | Cockapoo range |
| Toy or Miniature Poodle | Under 38cm tall | Small booster with high sides | Poodle range |
| French Bulldog | About 8 to 14kg | Wide medium seat, 14 to 20kg | French Bulldog range |
| Cocker Spaniel | About 13 to 15kg | Medium seat rated 18 to 20kg | Cocker Spaniel range |
| Staffordshire Bull Terrier | About 11 to 17kg | Sturdy seat rated 18 to 25kg | Staffie range |
| Standard Poodle | About 20 to 32kg | Large bed or extender | Poodle range |
| Golden Retriever | About 25 to 34kg | Large bed, extender or hammock | Golden Retriever range |
| Labrador | About 25 to 36kg | Large bed, extender or hammock | Labrador range |
Shape matters as well as weight. A long, low Dachshund needs inside length more than height. A broad chested French Bulldog or Staffie needs a wide, firm base. A tall Standard Poodle needs space to lie down rather than a booster with high walls.
Dog Seat Cover Chart by Car
Seat covers are sized by your back seat, not your dog. Measure the bench from door to door at the seat base and compare it with the cover width. Several of our hammocks are around 137cm wide, and one is listed at 125 to 145cm. Our covers are universal, so a quick measure is always worth it.
Small cars and hatchbacks
A cover that matches the bench sits flat and stays put. Side flaps help in a narrow cabin.
Small SUVs
A hammock keeps your dog out of the footwell. A hard base cover helps where rear legroom is tight.
Family SUVs
Wide benches and deep footwells suit a full hammock or a hard base cover for big dogs.
Nissan Qashqai · Kia Sportage · Hyundai Tucson · Volvo XC40 · MG HS
Between Two Sizes? Here Is How to Choose
Go up a size if
- Your puppy is still growing
- Your dog likes to stretch out on long drives
- Your dog is broad or long for their weight
- You plan to add a blanket or cushion
Stay with the smaller size if
- Your dog is small and likes a snug den
- Your dog slides about or tries to climb out
- Your back seat is narrow
- Your dog is fully grown and curls up tight
Puppies: for small breeds, buy for the adult size and pad the seat with a folded blanket for now. For large breeds that will outgrow any booster within months, a seat cover with a harness tether, or a back seat extender, is often better value from day one.
Our Dog Car Seats by Size
These are picks from our own range, sorted by weight limit. Every product is chosen for comfort and containment, and none of them is crash tested.
Small dogs, up to about 11kg
Console Seat and Carrier
Enclosed mesh seat for very small dogs on short trips.
View product Up to 8kg
Dog Booster Car Seat
Raised booster for toy breeds who like to see out.
View product Up to 9kg
Plush Small Dog Booster Seat
Soft, warm lining for small dogs who feel the cold.
View product Up to 10kg
Booster Seat and Travel Carrier
Padded seat that doubles as a carrier when you arrive.
View product Up to 11kg
Waterproof Plush Booster Seat
Waterproof base and storage pockets for treats and poo bags.
View productMedium dogs, about 12 to 26kg
Extra Stable Waterproof Seat
Firm, waterproof seat for the top end of small breeds.
View product Up to 14kg
Car Seat Bed with Removable Cushion
Low bed for dogs who prefer to lie down on longer drives.
View product Up to 18kg
Waterproof Medium Seat
A good match for Cocker Spaniels and many Staffies.
View product Up to 20kg
Medium Seat with Safety Leashes
Comes with tethers to clip to your dog's harness.
View product Up to 26kg
Extra Stable Seat for Bigger Dogs
The highest weight rating of our booster style seats.
View productLarge dogs, over 25kg
Large Dog Car Bed
Rated to about 54kg, with a thick cushion for big dogs.
View product 2 sizes
Back Seat Extender
Turns the footwell into a flat platform with 40cm walls.
View product 3 in 1
3 in 1 Cover with Extender
Hammock, bench cover and firm platform in one.
View product 137cm wide
Waterproof Hammock, 137cm
Mesh window and door flaps for any size of dog.
View product Boot
Boot Liner with Bumper Flap
For big dogs who ride behind a dog guard.
View productSafety and the Law
Highway Code Rule 57 says that when you are in a vehicle, you should make sure dogs are suitably restrained so they cannot distract you while driving or injure you, or themselves, if you stop quickly. It lists a seat belt harness, pet carrier, dog cage or dog guard as ways to do this.
A seat is not a restraint on its own. A booster or bed gives your dog a set place to sit, but it is the short tether clipped to a car harness that holds them. Never clip a tether to a collar, and keep it short enough that your dog cannot reach the front or hang over the side. Our seats and covers are for comfort and containment and are not crash tested.
Keep dogs in the back. A front airbag can hurt a dog badly, so the back seat or a secured boot is the place for any size of dog.
Dog Car Seat Size Questions
What size dog car seat do I need?
Weigh your dog and choose a seat rated at least 2 to 3kg above that weight. Then check the inside length is a little longer than your dog measured lying down, from nose to the base of the tail.
Should a dog car seat be bigger than the dog?
Slightly. Your dog should be able to turn round and lie down, but a seat that is far too big lets a small dog slide about on bends.
What weight can a dog booster seat hold?
Small boosters usually take up to 5 to 11kg, and medium seats up to 18 to 26kg. Above that, a large car bed or back seat extender is the better choice.
Can a large dog use a car seat?
Most raised boosters are too small for dogs over 25kg. A large dog does better on a car bed rated well above their weight, a back seat extender or a hammock, with a harness tether.
How do I know what size seat cover fits my car?
Measure your back seat from door to door at the seat base and choose a cover close to that width. The size is listed on each product page.
Find the Right Size and Buy Today
Shop by size, breed or car, and order the right seat with delivery across the UK. Not sure which size? Send us your dog's weight and car model on WhatsApp.
Shop all dog car seatsAsk on WhatsAppKeep reading: Best dog car seat UK guide · Are crash tested seats worth it? · Labrador seat guide · Cockapoo seat guide
