The Basic Rule: TSA Size and Weight Limits

The Transportation Security Administration (TSA) allows one carry-on bag and one personal item (like a purse or laptop bag) on most domestic flights. Your carry-on must fit in the overhead bin or under the seat in front of you. The standard size limit is 22 inches long, 14 inches wide, and 9 inches deep, though airlines may have slightly different rules—check your airline's website before packing.

Weight limits vary by airline. Most domestic carriers do not enforce a strict weight limit for carry-on bags, but international airlines often cap them at 26 pounds. If your bag is too large or heavy, you will be asked to check it at the gate, which means you lose access to it until you land. Measure your bag before you pack, or bring a small luggage scale to avoid surprises at the airport.

Key Takeaways

  • Liquids, gels, and aerosols must be 3.4 ounces or smaller per container and fit in a single quart-sized clear bag.
  • Electronics larger than a laptop (like a full-size printer or power drill) are prohibited; laptops, phones, and tablets are allowed.
  • Sharp objects like knives, box cutters, and ice picks are banned, but safety razors and small scissors (under 4 inches) are permitted.
  • Medications in original labeled containers are allowed, and you can bring more than the 3.4-ounce limit if they are medically necessary.
  • Your carry-on bag must fit the airline's size restrictions, which typically max out at 22 x 14 x 9 inches.

Liquids, Gels, and Aerosols: The 3-1-1 Rule

The TSA's 3-1-1 rule is the most important restriction to remember: each liquid, gel, or aerosol container can hold no more than 3.4 ounces (100 milliliters), all containers must fit inside one quart-sized clear plastic bag, and you can bring only one bag per person. This rule applies to toothpaste, shampoo, conditioner, lotion, sunscreen, deodorant, peanut butter, yogurt, honey, and anything else that flows or spreads.

Pack these items in a separate, straightforward-to-reach spot in your carry-on. At security, you will remove the bag and place it in the bin for screening. If a container is larger than 3.4 ounces, it will be confiscated, even if it is only half full. Buy travel-size bottles before you fly, or transfer products into small containers at home. Solid items like lip balm, solid deodorant, and bar soap do not count toward the liquid limit.

Medications and medical liquids (like saline solution or insulin) are exempt from the 3.4-ounce limit, but they must be in their original, labeled containers and declared to TSA officers. Inform the officer that you are carrying medication before you go through the scanner.

Electronics and Batteries You Can Bring

Laptops, tablets, e-readers, phones, and portable chargers are all allowed in carry-on luggage. You will need to remove your laptop and place it in a separate bin during security screening. Larger electronics like full-size printers, power tools, and game consoles are prohibited in both carry-on and checked bags.

Spare batteries have specific rules. Lithium-ion batteries (the kind in phones and laptops) are allowed in carry-on bags only—not in checked luggage. Spare lithium batteries must be in their original packaging or have their terminals taped to prevent short circuits. Alkaline batteries (standard AA, AAA, C, D, and 9-volt) are allowed in both carry-on and checked bags without restriction.

Do not pack e-cigarettes or vaping devices in checked luggage; they are only permitted in carry-on bags because of fire risk. The same rule applies to lighters—one lighter is allowed in your carry-on, but not in checked bags.

Sharp Objects and Tools: What Is Banned and What Is Not

Knives of any size, box cutters, ice picks, and razor blades are all prohibited in carry-on bags. Scissors are allowed only if the blades are shorter than 4 inches and the edges are rounded. Safety razors and straight razors are permitted, but cartridge razors and disposable razors are not.

Tools like screwdrivers, wrenches, and hammers are banned from carry-on bags but are allowed in checked luggage. Corkscrews and bottle openers are permitted in carry-on bags as long as they do not have a blade. Nail clippers and nail files are allowed. If you are traveling with tools for work, pack them in your checked bag instead.

Medications, Vitamins, and Medical Devices

Medications in their original, labeled containers are allowed in carry-on and checked bags. You do not need a prescription copy, but it is helpful to have one in case of questions. Bring enough medication for your entire trip plus a few extra days in case of delays. Syringes are permitted if they are accompanied by medication in a labeled container.

Vitamins, supplements, and over-the-counter medications are also allowed. Powder medications and supplements in containers larger than 12 ounces may require additional screening at the checkpoint. Medical devices like CPAP machines, inhalers, EpiPens, and glucose monitors are all permitted. Notify the TSA officer if you are carrying medical equipment so they can screen it appropriately.

Food, Drinks, and Perishables

Solid foods like sandwiches, fruit, cheese, and cookies are allowed through security and in your carry-on bag. Liquids and gels—including peanut butter, jam, honey, yogurt, and hummus—must follow the 3-1-1 rule. Frozen items are allowed only if they are completely solid when you go through security; if they have any liquid or gel, they will be confiscated.

You cannot bring an open beverage through security, but you can buy a drink after you pass the checkpoint and bring it on the plane. Some airlines provide complimentary beverages, so check before you pack. Alcohol is not allowed in carry-on bags, though you can pack it in checked luggage under specific rules that vary by airline.

Clothing, Documents, and Personal Items

There are no restrictions on clothing, shoes, belts, or accessories in carry-on bags. Pack your important documents—passport, ID, boarding pass, travel insurance, and hotel confirmations—in an straightforward-to-reach pocket. Make digital copies of these documents and email them to yourself as a backup.

Jewelry, watches, and eyeglasses are allowed. Lighters and matches are restricted as noted above. Books, magazines, and printed materials have no limits. Sports equipment like tennis rackets, golf clubs, and ski poles may be allowed in carry-on bags depending on the airline—contact your carrier before you pack.

Frequently Asked Questions

Can I bring a full-size bottle of perfume or cologne in my carry-on?

No. Perfume and cologne are liquids and must follow the 3-1-1 rule, so each container can hold no more than 3.4 ounces. Buy a travel-size bottle or transfer some into a small container before you fly.

What happens if I accidentally pack something prohibited?

TSA officers will confiscate the item at the security checkpoint. You will not be fined or delayed significantly, but you will lose the item. If you realize you have something prohibited before you reach security, you can leave it at the airport, mail it to yourself, or ask a friend to take it home.

Are gel insoles and shoe inserts allowed in carry-on bags?

Yes. Gel insoles are considered personal items and are allowed. However, if the gel is in a container larger than 3.4 ounces and not attached to a shoe, it may be subject to the 3-1-1 rule. To be safe, keep gel insoles in your shoes or in a small container that fits the liquid limit.

Can I bring my laptop charger and power bank on the plane?

Yes. Laptop chargers and power banks are allowed in carry-on bags. Power banks with lithium batteries must be in carry-on only, not checked luggage. Make sure the power bank is not damaged and the terminals are not exposed.

Do I need to declare my medications at security?

You do not have to declare most medications, but it is a good idea to inform the TSA officer if you are carrying syringes, large quantities, or medical devices. Having your medications in their original labeled containers makes the process faster and smoother.