Traveling with your dog or cat in the cabin requires an airline compliant pet carrier that fits underneath the airplane seat. Each airline publishes slightly different size limits for in-cabin pet carriers. This guide summarizes the typical requirements for major airlines and helps you choose the best soft-sided carrier for travel.

Most airlines allow soft-sided carriers that are slightly flexible and fit under the seat in front of you. The Mr. Peanut’s Gold Series Standard Size Expandable Pet Carrier is designed to meet the typical airline requirement of approximately 18" x 11" x 11".


Recommended Airline-Approved Pet Carriers

The following soft-sided carriers are designed for airline travel and are commonly used for in-cabin pet flights. Always confirm airline rules before traveling.


Alaska Airlines Pet Carrier Size

Typical in-cabin carrier dimensions:

  • 17" L x 11" W x 9.5" H

Soft-sided carriers that can compress slightly are typically allowed. Pets must remain inside the carrier under the seat for the duration of the flight.


American Airlines Pet Carrier Size

Typical in-cabin carrier dimensions:

  • 18" L x 11" W x 11" H

Soft-sided carriers are recommended because they can conform slightly to the under-seat space. The carrier must allow the pet to stand, turn around, and lie down comfortably.


Delta Air Lines Pet Carrier Size

Delta does not publish a universal carrier size because under-seat space varies by aircraft. However most compliant carriers are approximately:

  • 18" L x 11" W x 11" H

Soft-sided carriers are strongly recommended for Delta flights.


United Airlines Pet Carrier Size

Typical in-cabin carrier dimensions:

  • 18" L x 11" W x 11" H

United allows soft-sided carriers that fit under the seat. Your pet must remain inside the carrier during the flight.


Southwest Airlines Pet Carrier Size

Maximum pet carrier dimensions:

  • 18.5" L x 8.5" H x 13.5" W

Southwest is known for allowing slightly flexible soft-sided carriers that fit under the seat.


JetBlue Pet Carrier Size

Typical JetBlue carrier dimensions:

  • 17" L x 12.5" W x 8.5" H

JetBlue allows one pet per passenger and the carrier must remain under the seat in front of you.


Air France Pet Carrier Size

Maximum combined carrier dimensions typically allowed:

  • 18" x 11" x 11"

The pet and carrier combined must usually weigh less than 8 kg (17.6 lbs).


Lufthansa Pet Carrier Size

Typical in-cabin carrier dimensions:

  • 21.5" L x 15.5" W x 9" H

Pets must remain inside the carrier under the seat during the flight.


Air Canada Pet Carrier Size

Soft-sided carrier dimensions:

  • 21.5" L x 15.5" W x 10.5" H

Air Canada recommends soft carriers that fit under the seat and provide ventilation on multiple sides.


Choosing the Right Airline Pet Carrier

When selecting a carrier for airline travel, look for these features:

  • Soft-sided flexible construction
  • Ventilated mesh panels
  • Secure locking zippers
  • Comfortable padded shoulder strap
  • Expandable panels for added pet comfort

The Mr. Peanut’s Gold Series Expandable Carrier is designed specifically for airline travel and is used by thousands of pet owners flying with their pets in cabin.


Important Airline Pet Travel Tips

  • Always confirm pet policies with your airline before travel
  • Bring vaccination documentation if required
  • Arrive early to allow time for check-in
  • Ensure your pet can comfortably stand and turn inside the carrier

Airline policies may change, so always verify requirements with your airline before traveling.

Airline Pet Carrier Size Comparison

The table below compares typical in-cabin pet carrier size limits for major airlines. Soft-sided carriers are usually recommended because they can flex slightly to fit under the seat.

Airline Typical Carrier Size Limit Soft Carrier Allowed
Alaska Airlines 17" L x 11" W x 9.5" H Yes
American Airlines 18" L x 11" W x 11" H Yes
Delta Air Lines Approx. 18" x 11" x 11" Yes
United Airlines 18" L x 11" W x 11" H Yes
Southwest Airlines 18.5" L x 8.5" H x 13.5" W Yes
JetBlue 17" L x 12.5" W x 8.5" H Yes
Air Canada 21.5" L x 15.5" W x 10.5" H Yes
Lufthansa 21.5" L x 15.5" W x 9" H Yes
Air France Approx. 18" x 11" x 11" Yes

Tip: Soft-sided carriers are recommended for air travel because they can compress slightly to fit under the airplane seat.

Airline-Specific Pet Carrier Size Guide

Many pet parents search by airline because under-seat space and in-cabin pet carrier rules vary. The sections below summarize common airline pet carrier size guidance for popular airlines. Because aircraft and policies can change, always confirm directly with your airline before travel.

American Airlines Pet Carrier Size

American Airlines says soft-sided pet carriers are recommended and lists a typical in-cabin soft carrier size of 18" x 11" x 11". Hard-sided size limits vary by aircraft. This makes a flexible soft-sided carrier one of the safest options for most American Airlines flights.

Delta Pet Carrier Size

Delta says under-seat space varies by aircraft, but it recommends a soft-sided kennel with maximum dimensions of 18" x 11" x 11" because that size fits most aircraft types. For shoppers, that makes Delta one of the most important airline searches to target.

United Airlines Pet Carrier Size

United lists different limits for hard-sided and soft-sided pet carriers. For soft-sided carriers, United allows up to 18" x 11" x 11". This is one reason many travelers search phrases like “United Airlines pet carrier size” and “pet carrier under airplane seat.”

Alaska Airlines Pet Carrier Size

Alaska Airlines requires an appropriately sized carrier that fits under the seat at your feet. Because under-seat space can vary, flexible soft-sided carriers are generally the best choice for Alaska travelers who want a more forgiving fit.

Southwest Airlines Pet Carrier Size

Southwest allows one pet carrier per ticketed customer and limits the pet carrier to 18.5" L x 13.5" W x 8.5" H. Southwest shoppers often search for a low-profile soft carrier because the height limit is tighter than some other airlines.

JetBlue Pet Carrier Size

JetBlue publishes one of the clearest in-cabin pet carrier limits: 17" L x 12.5" W x 8.5" H. Because the height allowance is compact, JetBlue travelers are often highly focused on exact carrier dimensions before buying.

Air Canada Pet Carrier Size

Air Canada publishes aircraft-specific pet carrier dimensions for in-cabin travel. On some aircraft, the soft-sided maximum is 17" x 16" x 8", while on others it can be as large as 22" x 16" x 10". This makes Air Canada an excellent airline to include on a pet carrier size guide page.

Lufthansa Pet Carrier Size

Lufthansa allows small dogs and cats in the cabin when the pet and carrier together weigh no more than 8 kg (17.6 lb). Lufthansa’s maximum carrier dimensions are 55 x 40 x 23 cm (about 21.7" x 15.7" x 9.1").

KLM Pet Carrier Size

KLM allows one cat or dog in the cabin in a closed pet travel bag or kennel with a maximum size of 46 x 28 x 24 cm (about 18" x 11" x 9"). The combined pet-and-carrier weight limit is 8 kg (17.6 lb).

British Airways Pet Policy

British Airways generally does not allow pets in the cabin on regular routes, except for recognized assistance dogs. For that reason, British Airways may be worth mentioning on your guide page as a note, but it is less important for an in-cabin pet carrier comparison section.

How to Choose the Best Airline-Friendly Pet Carrier

  • Choose soft-sided construction: most airlines prefer soft carriers because they can compress slightly under the seat.
  • Check both dimensions and weight: some airlines care about size, while others also enforce a combined pet-and-carrier weight limit.
  • Look for strong ventilation: mesh panels on multiple sides help meet common airline expectations.
  • Prioritize under-seat fit: many buyers search for “pet carriers that fit under airplane seat” because that is the key approval factor at the airport.

Popular Airline Pet Carrier Searches

This page is designed to help answer common travel questions such as:

  • American Airlines pet carrier size
  • Delta pet carrier dimensions
  • United Airlines pet carrier size
  • JetBlue pet carrier size
  • Southwest pet carrier dimensions
  • Air Canada pet carrier size
  • Lufthansa pet carrier dimensions
  • KLM pet carrier size
  • Pet carrier under airplane seat
  • Airline approved pet carrier size

Important: Airline pet policies can change, and under-seat space may differ by aircraft. Always verify your airline’s current pet travel requirements before you fly.