Whether you’re purposefully packing light or simply supplementing your checked luggage with a few items you would like to keep handy during a flight, it’s important to keep size top of mind when packing a carry-on 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.
Check TSA’s website and the carry-on restrictions set by the airline before you get packing and you’ll be well on your way to a less stressful flight.
TSA carry-on restrictions
Before you even make it to your departure gate, you have to clear a TSA checkpoint, which means first and foremost, you must adhere to the carry-on liquid restrictions (and other rules) in order to make it through security.
Pack liquids, creams, pastes and gels in containers no larger than 3.4 ounces (or 100 milliliters), then put these in a clear zip-top container. Any larger liquids will have to go into checked baggage.
There are a few exceptions — certain liquid medications and baby formula or breast milk are exempt from these restrictions.
The only flammables allowed in a carry-on are cigars, cigarettes, disposable and Zippo lighters, and dry batteries (like AAs or AAAs).
Camping and sports equipment
You can carry-on an air mattress with a built-in pump (by following special instructions), antlers, basketballs, footballs, baseballs, soccer balls, bike chains and bike pumps. Bicycle allowances vary by airline, but baseball bats, bear spray and bear bangers are never allowed — nor is aerosol insecticide.
There are a number of prohibited items, including knives, firearms and box cutters. A full list of which can be found on TSA’s website.
Specific airline carry-on restrictions
Once you make it through the security checkpoint, carry-on bag restrictions depend on the airline. Every airline has slightly different rules on the size, weight and how many bags you can bring onboard the plane.
As a general rule, a personal item typically includes small backpacks, purses, briefcases, diaper bags, camera bags or items 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:
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 restrictions, but it says that passengers should be able to lift items that go in an overhead bin.
» Learn more: Guide to Alaska Airlines baggage and other fees
For an American Airlines flight, passengers get one personal item and one carry-on, no matter what type of fare purchased (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 flyers are permitted 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 combined length plus width plus height of baggage must not exceed 45 linear inches.
For personal items, but Delta says size examples are purses, small backpacks and laptops.
Three places have weight restrictions: Singapore (7 kg, about 15.4 pounds), Beijing (10 kg, about 22 pounds) and Shanghai (10 kg, about 22 pounds).
Not all JetBlue passengers are allowed the same carry-on items. Passengers who purchased 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 restrictions for carry-on luggage on JetBlue.
» Learn more: Guide to JetBlue baggage, cancellation and other fees
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 restrictions for carry-on items.
» Learn more: The guide to Southwest baggage and other fees
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 permitted 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 restrictions for carry-ons.
The bottom line
No matter which airline you fly with, first make sure you know what size carry-on you’re permitted to bring onboard and are familiar with (and prepared for) TSA’s carry-on restrictions, too. Then, you can expect a smoother and less stressful airport and airliner experience.
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