On most US airlines there's no weight limit for a dog in the cabin. Your dog just has to fit in a carrier that goes under the seat, around 18 × 11 × 11 inches at most, and be able to stand and turn around inside. European airlines are stricter: usually 8 kg (about 17.6 lb) including the carrier.
Key facts
- United, Delta and other US airlines set a carrier size, not a dog weight limit (as of October 2026).
- The largest common US soft carrier limit is 18 × 11 × 11 in (United, Delta, American).
- American Airlines' 3-cabin A321T is the exception: pet plus carrier can't exceed 20 lb (9.07 kg).
- Lufthansa, Air France, KLM and Turkish Airlines cap pet plus carrier at 8 kg in the cabin.
- Your dog's standing height has to be less than the carrier's inside height.
Is there a weight limit for dogs in the cabin?
It depends on where the airline is based.
| Airline | Cabin weight limit | Carrier limit (L × W × H) |
|---|---|---|
| United | None | Soft 18 × 11 × 11 in; hard 17.5 × 12 × 9 in |
| Delta | None stated | 18 × 11 × 11 in |
| American | None, except 20 lb incl. carrier on the A321T | Soft 18 × 11 × 11 in; hard 19 × 13 × 9 in (mainline) |
| Alaska | None found | 17 × 11 × 9.5 in |
| JetBlue | None stated | 17 × 12.5 × 8.5 in |
| Air Canada | None published | 16 × 17 × 8 in on most jets |
| Lufthansa | 8 kg incl. carrier | 55 × 40 × 23 cm |
| Air France | Under 8 kg (17.64 lb) incl. carrier | Check with airline |
| KLM | 8 kg (17.6 lb) incl. carrier | 46 × 28 × 24 cm |
| Turkish Airlines | 8 kg incl. carrier | 40 × 30 × 23 cm |
From each airline's pet policy page, checked October 2026. Limits can vary by aircraft; check yours when you book.
US and Canadian airlines describe the limit in terms of comfort instead of weight. Delta says your pet must be able to move around without touching or sticking out of the sides of the kennel. Air Canada says your pet must be able to stand, turn around and lie down, with no part extending outside the carrier. IATA's guidance for cabin pets says the same, and adds that "only very small dogs or cats" fit under aircraft seats.
Can a 20 lb dog fly in the cabin?
Sometimes. Weight alone doesn't answer it:
- On European airlines with an 8 kg rule: no. 8 kg is about 17.6 lb, and that includes the carrier.
- On American's A321T: no. The dog and carrier together must weigh 20 lb or less, and they're weighed at check-in.
- On United, Delta and most other US flights: possibly, if your dog fits in a carrier within the airline's size limit and can stand and turn around in it. A long-legged or tall 20 lb dog may not fit; a compact, low dog of the same weight might.
The same logic applies to a 25, 30 or 40 lb dog. There's no airline rule that bans them by weight, but very few dogs that heavy can stand up in a carrier around 11 inches tall.
What does "dog carrier for 20 lb dog" mean?
When a carrier is sold as fitting a 20 lb or 30 lb dog, that's the maker's load rating: the weight the frame and straps can hold. It isn't an airline rule, and it doesn't tell you whether your dog can stand up inside. A carrier rated for 30 lb can still be over your airline's size limit. Check the carrier's outside dimensions against your airline's limit, and its inside dimensions against your dog. Our airline-approved pet carrier guide explains why "airline approved" labels are marketing.
How to measure your dog for an in-cabin carrier
Use the same measurements IATA uses for travel crates. Measure with your dog standing naturally on a flat floor.
- Standing height: floor to the top of the head or the tips of upright ears, whichever is higher.
- Length: tip of the nose to the base of the tail.
- Width: across the shoulders or the widest point.
- Weight: weigh your dog in the carrier if you're flying an airline with a weight cap.
Then compare with the carrier's inside dimensions, which are smaller than the outside numbers the airline limits:
- If your dog's standing height is more than the carrier's inside height, it won't fit. It would have to crouch, and airlines can refuse it.
- Your dog needs to lie down naturally and turn around. For crates in the hold, IATA sets the minimum inside length at nose-to-tail-base plus half the leg height. Cabin carriers are rarely that long, but a dog much longer than the carrier will be cramped.
- Soft carriers can squash under the seat. IATA warns this can reduce airflow, so don't count on the sides flexing to make room.
To check a carrier against every airline at once, enter its size in our pet carrier size checker.
Height is usually what fails
Most under-seat limits are 8.5 to 11 inches tall. With a carrier's base, frame and padding, the inside height is less than that. On Air Canada's most common jets the limit is 8 inches, so only very small pets fit. If you fly more than one airline, size the carrier to the smallest limit on your trip, then check that your dog still fits inside it.
What if my dog is too big for the cabin?
You still have options, though fewer than you might expect:
- The hold, as checked baggage. Alaska, Air Canada, WestJet, Air France, KLM and Lufthansa carry larger dogs in a hard crate in the hold. Size the crate with our dog crate size calculator.
- Cargo. United and Delta don't accept pets as checked baggage, except for some military and State Department travelers. American Airlines carries pets through American Airlines Cargo. See flying pets in cargo.
- Dog charters and the few large-dog cabin options. See airlines that allow large dogs in the cabin.
- Don't fly. For shorter distances, driving may be easier on a big dog.
Trained service dogs follow separate rules and aren't limited by carrier size. Emotional support animals travel as regular pets.
Questions people ask
How big can a dog be to fly in the cabin?
On US airlines there's no weight limit; your dog must fit in a carrier no larger than the airline's under-seat limit (often 18 × 11 × 11 in) and be able to stand and turn around. European airlines usually cap pet plus carrier at 8 kg.
Can a 30 lb dog fly in the cabin?
Not on airlines with an 8 kg or 20 lb cap. On United, Delta and similar airlines there's no weight rule, but a 30 lb dog would have to fit in a carrier around 18 × 11 × 11 in, which few can.
Does the dog's weight include the carrier?
Where there's a limit, yes. Lufthansa, Air France, KLM and Turkish Airlines count pet and carrier together, and so does American on its A321T.
Can my dog's head stick out of the carrier?
No. Your dog must stay fully inside the closed carrier, under the seat, for the whole flight.
Can I buy a seat for my dog?
Some airlines let you buy a seat for a second pet carrier, but the carrier still goes under the seat in front. A seat doesn't let a bigger dog fly in the cabin.
Sources
- United Airlines: Traveling with pets
- Delta Air Lines: Pet travel
- American Airlines: Pets
- Alaska Airlines: Pets in cabin
- JetBlue: Traveling with pets
- WestJet: Travelling with pets
- Turkish Airlines: Transport in the cabin
- Air Canada: Travelling with pets
- Lufthansa: Animals in the cabin
- Air France: Traveling with your dog or cat
- KLM: Travelling with pets
- IATA: Guidance for passengers traveling with their dog or cat in the cabin
- IATA: Traveling with pets
