Whether you’re purposefully packing light or supplementing your checked luggage, it’s important to keep Transportation Security Administration (TSA) carry-on luggage size in mind when packing a bag and heading to the airport.

After all, not all airlines allow full-size carry-ons for free, and most have slightly different rules on what size those bags can be. Don’t get caught unaware at the gate; hefty baggage fees and inconvenience may await.

Here’s what you need to know about airline and TSA carry-on size allowances.

Airline-specific carry-on luggage rules

Airline carry-on dimensions differ depending on the carrier. When purchasing your flight, you’ll be able to see your carry-on and personal item limits.

A personal item is typically a small backpack, purse, briefcase, diaper bag, camera bag or any item of a similar size that can fit underneath the seat in front of you. A carry-on bag could be anything from a large backpack to a small rolling suitcase. But it’s less shape than size that matters, so here are carry-on luggage size restrictions for each of the major domestic airlines:

Alaska Airlines

On an Alaska Airlines flight, you can bring a carry-on and a personal item for free.

Carry-on bags are limited to 22 inches long, 14 inches wide and 9 inches high including wheels and handles. All three measurements shouldn’t add up to more than 45 inches.

For personal items, Alaska offers examples of a purse, laptop or briefcase.

Alaska doesn't list weight limits, but it says that passengers should be able to lift items that go in an overhead bin.

American Airlines

For an American Airlines flight, passengers get one personal item and one carry-on, no matter what type of fare is bought (elite members included).

Carry-on bags shouldn’t be larger than 22 inches long, 14 inches wide and 9 inches high including handles and wheels.

Dimensions of personal items should not exceed 18 inches long, 14 inches wide and 8 inches high.

There are no weight restrictions for carry-on luggage.

Delta Air Lines

Delta flyers are allowed one carry-on bag and one personal item.

Including wheels and handles, measurements may not exceed 22 inches long, 14 inches width and 9 inches high. The total length plus width plus height of baggage must not exceed 45 linear inches.

For personal items, Delta says size examples are purses, small backpacks and laptops.

Three places have weight limits: Singapore (7 kg, about 15.4 pounds), Beijing (10 kg, about 22 pounds) and Shanghai (10 kg, about 22 pounds).

Frontier

Frontier charges for both checked luggage and carry-on bags, and the price depends on the route you fly. It also varies depending on if you buy the bags before via the web or mobile app, at the ticket desk, or the boarding gate.

Carry-on bags must weigh less than 35 pounds and must not exceed 10 inches deep, 16 inches wide and 24 inches high. Bags must fit in the overhead bins.

Checked bags must be no longer than 62 linear inches (length + width + depth) and must weigh under 40 pounds. Bags weighing more than 40 pounds will incur additional charges per bag per direction. Bags weighing 41-50 pounds will cost you $50 more and bags weighing 51-100 pounds will cost $100 more.

Personal items cannot exceed 8 inches deep, 18 inches wide and 14 inches high.

JetBlue

Not all JetBlue passengers are allowed the same carry-on items. Passengers who bought Basic Blue fares get one personal item (except Mosaic customers who always get a carry-on). Blue, Extra Blue, Blue Plus and Mint fares allow one carry-on and one personal item.

Including wheels and handles, length, width and height measurements may not exceed 22 inches long, 14 inches wide and 9 inches high.

Personal items can be no more than 17 inches long, 13 inches wide and 9 inches high or smaller to fit under the seat in front of you.

There are no weight limits for carry-on luggage on JetBlue.

Southwest Airlines

Southwest is known for having a generous free checked luggage allowance, but carry-on restrictions are similar to most other airlines — one personal item and one carry-on per traveler.

Carry-on measurements should not exceed 24 inches long, 16 inches wide and 10 inches high.

Personal items are limited to 18.5 inches long, 8.5 inches wide and 13.5 inches high.

Southwest doesn't list weight limits for carry-on items.

United Airlines

Most travelers flying with United can bring one carry-on and one personal item, but if you’re traveling on a basic economy fare, you’re allowed one personal item only (unless you’re a MileagePlus Premier Member, are traveling internationally or have a MileagePlus credit card, like the United℠ Business Card).

Including handles and wheels, the maximum dimensions for a carry-on are 22 inches long, 14 inches wide and 9 inches high.

Personal items are limited to 17 inches long, 10 inches wide and 9 inches high.

United doesn't publish weight limits for carry-ons.

Depending on the airline you fly with as well as how long you’re traveling for, you might wonder whether you’re better off traveling with a checked bag rather than a carry-on. This can be especially relevant if you’ve got some liquids with you that exceed the TSA carry-on liquid limits.

WANT TSA PRECHECK FOR FREE?

A number of popular travel credit cards reimburse you for the application fee for trusted traveler programs like TSA PreCheck and Global Entry. Among them:

Cards with TSA benefits

Bank of America® Premium Rewards® credit card

NerdWallet Rating

NerdWallet's ratings are determined by our editorial team. The scoring formula takes into account the type of card being reviewed (such as cash back, travel or balance transfer) and the card's rates, fees, rewards and other features.

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on Bank of America's website

United℠ Explorer Card

NerdWallet Rating

NerdWallet's ratings are determined by our editorial team. The scoring formula takes into account the type of card being reviewed (such as cash back, travel or balance transfer) and the card's rates, fees, rewards and other features.

Apply now

on Chase's website

Chase Sapphire Reserve®

NerdWallet Rating

NerdWallet's ratings are determined by our editorial team. The scoring formula takes into account the type of card being reviewed (such as cash back, travel or balance transfer) and the card's rates, fees, rewards and other features.

Apply now

on Chase's website

Capital One Venture Rewards Credit Card

NerdWallet Rating

NerdWallet's ratings are determined by our editorial team. The scoring formula takes into account the type of card being reviewed (such as cash back, travel or balance transfer) and the card's rates, fees, rewards and other features.

Read Review

Annual fee

$95

$0 intro for the first year, then $95

$550

$95

Benefit

Statement credit of up to $100 as reimbursement when you charge the application fee for TSA PreCheck or Global Entry to the card. Available once every 4 years.

Statement credit of up to $100 as reimbursement when you charge the application fee for TSA PreCheck, Global Entry or NEXUS to the card. Available once every 4 years.

Statement credit of up to $100 as reimbursement when you charge the application fee for TSA PreCheck, Global Entry or NEXUS to the card. Available once every 4 years.

Statement credit of up to $100 as reimbursement when you charge the application fee for TSA PreCheck or Global Entry to the card. Available once every 4 years.

Learn more

Read Review

Read Review

Read Review

Read Review

How to get credit card reimbursement

If your credit card offers reimbursement for the application fee for programs like TSA PreCheck or Global Entry, you must pay the fee with the card. You cannot submit a claim for reimbursement if you paid with some other method. Reimbursement will usually appear as a statement credit in your account within two months.

Cards typically offer reimbursement of only one fee once every four to five years. Check the terms and conditions of your card for the specific rules that apply. Note also that these cards only reimburse the application fee for a trusted traveler program. They don't automatically enroll you in the program or guarantee that you'll be accepted by the program. You still have to apply and go through the required screening, which in the case of TSA PreCheck and Global Entry includes an in-person appointment.

Credit cards that reimburse TSA PreCheck fees

Aeroplan® Credit Card.

Bank of America® Premium Rewards® credit card

Capital One Venture X Rewards Credit Card.

Chase Sapphire Reserve®.

Citi® / AAdvantage® Executive World Elite Mastercard®.

Delta SkyMiles® Platinum American Express Card.

Delta SkyMiles® Reserve American Express Card.

IHG® One Rewards Premier Business Credit Card.

IHG® One Rewards Premier Credit Card.

Marriott Bonvoy Brilliant® American Express® Card.

The Platinum Card® from American Express.

Southwest® Rapid Rewards® Performance Business Credit Card.

United Club℠ Infinite Card.

United℠ Explorer Card.

United Quest℠ Card.

U.S. Bank Altitude™ Reserve Visa Infinite® Card.

Terms apply.

» SEE the best credit cards that pay for TSA PreCheck and Global Entry

TSA liquid limits

Before you even make it to your departure gate, you have to clear a TSA checkpoint. This means you must adhere to the TSA liquid limit in order to make it through security.

How many ounces are allowed on a plane?

Containers that are 3.4 ounces or less are allowed, but there are other rules to keep in mind as well.

Carry-on liquid limit

The TSA liquid rule — also known as the 3-1-1 rule (3 ounces, 1 bag per 1 person) — is straightforward: "You are allowed to bring a quart-sized bag of liquids, aerosols, gels, creams and pastes in your carry-on bag and through the checkpoint. These are limited to travel-sized containers that are 3.4 ounces (100 milliliters) or less per item." Any liquids in larger containers will have to go into checked baggage (and are subject to overweight fees).

A basic clear, zip-top container qualifies as an eligible quart-size bag for passing through security.