Find out if your personal item will fit under the seat in front of you.
Here are some of the most popular U.S. airlines' underseat guidelines and personal item sizes.
According to its carry-on guidelines, personal items should not exceed 17 inches by 13 inches by six inches.
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When bringing a pet carrier on board, only one additional carry-on or personal item is allowed.
Allegiant Air
Passengers can place one personal item under the seat in front of them.
The item should not exceed 18 inches by 14 inches by eight inches.
Pet carriers can be used alongside a personal item or a paid carry-on bag.
A fee is also required.
Frontier Airlines
Frontier Airlines includes totes, computer bags, and kids' backpacks as personal items.
Underseat baggage should be no larger than 14 inches tall, 18 inches wide, and eight inches long.
If a pet carrier fits these dimensions, it can be used as one of two included carry-on items.
Underseat luggage cannot exceed 17 inches by 13 inches by eight inches.
These dimensions include pet carriers, which are considered personal items.
The item must not exceed roughly 16 inches by 12 inches by four inches.
Southwest Airlines
Southwest allows purses, briefcases, and laptop bags as underseat luggage.
Pet carriers count as personal items or carry-on bags.
Pillows, including neck pillows, must fit inside the personal item.
A pet carrier will count as one of your carry-on items.
