The TSA's Basic Rules for Carry-On Items

The Transportation Security Administration (TSA) allows you to bring one carry-on bag and one personal item (like a purse or laptop bag) through security. Your carry-on must fit in the overhead bin or under the seat in front of you—most airlines use a size limit of 22 inches long, 14 inches wide, and 9 inches deep, though some budget carriers are stricter. The TSA does not limit what category of items you bring, only specific prohibited items and liquids.

The real constraint is not what you can bring, but what you cannot. Weapons, tools longer than 7 inches, and certain sporting equipment are banned. Liquids and gels—including shampoo, toothpaste, peanut butter, and yogurt—must follow the 3-1-1 rule: each container holds 3.4 ounces or less, all containers fit in one quart-sized clear plastic bag, and you pack only one bag per person.

Key Takeaways

  • Liquids and gels must be 3.4 ounces or smaller per container, all packed in a single quart-sized clear bag that you remove at security.
  • Solid foods, medications, and electronics (phones, laptops, cameras) are allowed in carry-on bags with no size or quantity limit.
  • Knives, tools, and weapons are prohibited; scissors with blades shorter than 4 inches are allowed.
  • Batteries, lighters, and vaping devices have specific rules—spare lithium batteries must be in carry-on, not checked luggage.
  • Different airlines enforce different size limits, so check your carrier's website before packing to avoid gate-checking your bag.

Everyday Items You Can Bring

Clothing, shoes, underwear, socks, and jackets have no restrictions. Electronics including phones, tablets, laptops, cameras, and headphones are fine. You can bring a book, e-reader, or notebook. Solid foods—sandwiches, fruit, granola bars, cheese—are allowed, though fresh meat, seafood, and some dairy products cannot cross international borders.

Medications in their original labeled containers are permitted. Bring a copy of your prescription or a doctor's letter if you are carrying large quantities or controlled substances. Eyeglasses, contact lenses, and contact lens solution are allowed. You can pack a phone charger, power bank, and cables. Deodorant (solid stick only, not spray or gel) is allowed.

The Liquid and Gel Rule in Detail

The 3-1-1 rule applies to anything that flows, spreads, or sprays at room temperature. This includes shampoo, conditioner, body wash, lotion, sunscreen, toothpaste, deodorant (gel or spray), mascara, liquid eyeliner, foundation, concealer, lip gloss, peanut butter, jam, honey, and yogurt. Solid deodorant, bar soap, and solid perfume are not liquids and do not count.

Pack all liquid containers in a single clear quart-sized plastic bag—the kind you can buy at any drugstore or get free at airport security. You remove this bag at the security checkpoint and place it in the bin with your shoes and electronics. If your bag does not fit in the quart-sized bag, the TSA officer will ask you to throw out the excess or check the item.

International flights have the same 3-1-1 rule for liquids in carry-on. If you are connecting through a US airport, liquids you buy after security at your first airport must also follow 3-1-1 for the second flight.

Electronics and Batteries

Laptops, tablets, and large electronics must be removed from your bag at security and scanned separately. Phones, headphones, and small cameras can stay in your bag. Power banks and portable chargers are allowed, but spare lithium batteries must go in carry-on, never in checked luggage—the airline will refuse them in checked bags because of fire risk.

Lighters are prohibited in both carry-on and checked bags, with one exception: a single lighter in your pocket or a lighter case is allowed in carry-on only if you are not checking a bag. Vaping devices and e-cigarettes are allowed in carry-on but prohibited in checked luggage. Matches are prohibited entirely.

Tools, Knives, and Sporting Equipment

Knives of any size are prohibited in carry-on. Scissors with blades shorter than 4 inches are allowed. Tools longer than 7 inches are prohibited—this includes most screwdrivers, wrenches, and hammers. Nail clippers, tweezers, and small multi-tools with blades under 4 inches are permitted.

Sporting equipment rules vary by item. Baseball bats, cricket bats, and hockey sticks are prohibited in carry-on but allowed in checked bags. Golf clubs, ski poles, and fishing rods are allowed in checked bags only. Tennis rackets, badminton rackets, and squash rackets are allowed in carry-on. If you are traveling with specialized sports gear, check the TSA website or call your airline before you pack.

What Happens at Security if You Pack Something Prohibited

If a TSA officer finds a prohibited item in your carry-on, you have three choices: check the bag if your airline allows it, throw the item away, or leave security and mail it to yourself. You cannot bring it back through the checkpoint. If you are unsure whether something is allowed, ask a TSA officer before you get in line—they can tell you on the spot.

Prohibited items found in checked luggage are handled differently. The TSA may confiscate the item, damage your bag to remove it, or charge you a fee. To avoid this, pack prohibited items nowhere in your luggage—not in carry-on and not in checked bags.

Airline-Specific Size and Weight Rules

The TSA sets security rules, but individual airlines set size limits. Most major carriers (United, American, Delta, Southwest) allow carry-on bags up to 22 x 14 x 9 inches. Budget airlines like Spirit and Frontier enforce smaller limits—often 21 x 14 x 10 inches—and may charge a gate-check fee if your bag is oversized. Some airlines also charge for a second carry-on item (your personal item may be free, but a rolling bag may not be).

Check your airline's website before you pack. If your bag is borderline, pack lighter so it compresses, or plan to check it. Gate-checking a carry-on bag at the last minute is free, but it means your bag arrives after you do and you cannot access it during the flight.

Frequently Asked Questions

Can I bring a full-size bottle of shampoo if I pack it in checked luggage?

Yes. The 3-1-1 liquid rule applies only to carry-on bags. In checked luggage, you can pack full-size bottles of shampoo, lotion, sunscreen, and other liquids with no limit, as long as the total weight of your checked bag does not exceed your airline's limit (usually 50 pounds).

Are solid perfume and deodorant allowed in carry-on?

Solid deodorant and solid perfume are allowed in carry-on because they are not liquids. Spray deodorant and liquid perfume must follow the 3-1-1 rule. If you are unsure whether your product is solid or liquid, check the label or test it—if it spreads or flows, it counts as a liquid.

Can I bring a power bank on the plane?

Yes, power banks are allowed in carry-on bags. They must go in carry-on, not checked luggage, because of lithium battery fire risk. Most airlines allow power banks up to 100 watt-hours; check your airline's website if your power bank is very large.

What if I forget my medications at home and need to buy them at the airport?

You can buy over-the-counter medications (pain relievers, cold medicine, antacids) at airport shops and bring them on the plane in their original packaging. If you need a prescription medication, you will need to visit an airport pharmacy or urgent care clinic, which may take time. Pack medications in your carry-on before you leave home to avoid this problem.

Can I bring a lighter or matches?

Lighters and matches are prohibited in both carry-on and checked bags, with one narrow exception: a single lighter in your pocket or a lighter case is allowed in carry-on only if you are not checking a bag. For most travelers, the answer is no—do not pack either one.