Pet carrier size limits by airline (under-seat) and carriers that fit
✓ Product dimensions checked against each manufacturer's official page; airline limits from our dated airline pages.
Each limit comes from the max carrier size on our airline page, which links to the official airline source and shows when we last verified it.
| Airline | Max carrier (L × W × H) | Type | Carriers within the limit |
|---|---|---|---|
| Air Canada Most mainline jets | 43 × 40 × 20 cm | Soft-sided only | none of ours |
| Air Canada Dash 8-400 / E175 / CRJ900 | 55 × 40 × 27 cm | Soft-sided only | Sherpa Original Deluxe Pet Carrier Small, Sherpa Original Deluxe Pet Carrier Medium, Sleepypod Air, Sleepypod Atom, SturdiBag Pro 3.0 Travel Pet Carrier Small |
| Air Canada Widebody Business Class | 41 × 21 × 28 cm | Soft-sided only | none of ours |
| Air France Cabin | 46 × 28 × 24 cm Air France gives no axis labels; read as L x W x H. | Soft-sided only | Sherpa Original Deluxe Pet Carrier Small, SturdiBag Pro 3.0 Travel Pet Carrier Small |
| Alaska Airlines (and Hawaiian Airlines) Cabin | 17 × 11 × 9.5 in Read as L x W x H. | Soft-sided only | Sherpa Original Deluxe Pet Carrier Small |
| American Airlines Soft-sided (recommended) | 18 × 11 × 11 in Read as L x W x H. | Soft-sided limit | Sherpa Original Deluxe Pet Carrier Small, Sherpa Original Deluxe Pet Carrier Medium, Sleepypod Air, Sleepypod Atom, SturdiBag Pro 3.0 Travel Pet Carrier Small |
| American Airlines Hard-sided, mainline | 19 × 13 × 9 in Read as L x W x H. | Hard-sided limit | no hard-sided carriers listed |
| American Airlines Hard-sided, American Eagle | 16 × 12 × 8 in Read as L x W x H. | Hard-sided limit | no hard-sided carriers listed |
| Delta Air Lines Recommended soft-sided kennel | 18 × 11 × 11 in Read as L x W x H. Delta says the real limit depends on the aircraft's under-seat space. | Soft-sided limit | Sherpa Original Deluxe Pet Carrier Small, Sherpa Original Deluxe Pet Carrier Medium, Sleepypod Air, Sleepypod Atom, SturdiBag Pro 3.0 Travel Pet Carrier Small |
| JetBlue Cabin (soft or hard) | 17 × 12.5 × 8.5 in Read as L x W x H. | Soft or hard | Sherpa Original Deluxe Pet Carrier Small |
| Lufthansa Cabin | 55 × 40 × 23 cm Read as L x W x H. Lufthansa also states a 118 cm total. | Soft-sided only | Sherpa Original Deluxe Pet Carrier Small |
| United Airlines Soft-sided | 18 × 11 × 11 in United lists 11 x 18 x 11 in without axis labels; read as H x L x W. United also says carriers can be no more than 10 in tall on the Boeing 737 MAX. | Soft-sided limit | Sherpa Original Deluxe Pet Carrier Small, Sherpa Original Deluxe Pet Carrier Medium, Sleepypod Air, Sleepypod Atom, SturdiBag Pro 3.0 Travel Pet Carrier Small |
| United Airlines Soft-sided, Boeing 737 MAX | 18 × 11 × 10 in United's soft-sided limit with its 10 in maximum height on the Boeing 737 MAX applied. | Soft-sided limit | Sherpa Original Deluxe Pet Carrier Small, SturdiBag Pro 3.0 Travel Pet Carrier Small |
| United Airlines Hard-sided | 17.5 × 12 × 9 in United lists 9 x 17.5 x 12 in without axis labels; read as H x L x W. | Hard-sided limit | no hard-sided carriers listed |
Not listed (no confirmed cabin carrier size, or no pets in the cabin): British Airways, Korean Air, Southwest Airlines.
More guides
- Best airline-approved soft pet carriers: sizes vs. under-seat limits
- IATA-style hard crates for flying pets in the hold or as cargo
- Pet carrier backpacks for flying: do they fit under the seat?
- Travel water bowls for dogs and cats: collapsible and nesting options
- All pet travel products
Affiliate disclosure: some links on this page may be affiliate links; if you buy through them we may earn a commission at no extra cost to you. It never changes the dimensions or fit results shown. We have not tested these products ourselves: every figure comes from the linked manufacturer page. Disclosure.