The TSA's Basic Rules for Carry-On Items

The Transportation Security Administration (TSA) allows most everyday items in your carry-on bag, but there are hard limits on liquids, gels, sharp objects, and anything that could be used as a weapon. The single biggest restriction is the 3-1-1 rule for liquids: containers of 3.4 ounces (100 milliliters) or smaller, all fitting into one quart-sized clear plastic bag, one bag per passenger. Everything else — clothing, books, electronics, toiletries in solid form — travels freely as long as it fits in your bag and passes through the X-ray machine.

What matters most is that TSA officers at your airport make the final call. The rules are consistent across all U.S. airports, but an officer can refuse an item even if it technically meets the size rules. If you are unsure about something specific, you can text a photo to the TSA's Ask TSA service on Twitter or Facebook before you pack.

Key Takeaways

  • Liquids, gels, and creams must be 3.4 ounces or smaller and fit in one quart-sized clear bag; this includes shampoo, lotion, peanut butter, and yogurt.
  • Sharp objects like razors, knives, and scissors are prohibited in carry-on bags but allowed in checked luggage.
  • Electronics including laptops, phones, and tablets are allowed and will be removed for X-ray screening.
  • Solid foods, books, clothing, and personal hygiene items in solid form (deodorant stick, solid perfume) have no restrictions.
  • Lighters, flammables, and tools longer than 7 inches are not allowed in carry-on bags.

Liquids, Gels, and Creams: The 3-1-1 Rule Explained

The 3-1-1 rule exists because the TSA cannot easily screen large quantities of liquid at security checkpoints. Any substance that flows, spreads, or sprays counts as a liquid or gel — even if it is thick. This includes shampoo, conditioner, body wash, lotion, sunscreen, toothpaste, deodorant (gel or cream), peanut butter, jam, honey, yogurt, pudding, and mascara.

Pack these items in a single quart-sized clear plastic bag (roughly 7 inches by 8 inches). You can buy pre-made TSA-compliant bags at most drugstores, or use any clear freezer bag that size. Each container inside must be 3.4 ounces or smaller. You do not have to fill the bag completely — it just has to hold everything. At security, remove the bag from your carry-on and place it in the bin for X-ray screening.

Solid deodorant, solid perfume, lipstick, and bar soap do not count as liquids and can travel in your regular carry-on without the bag. Medications in liquid form (like liquid ibuprofen) are allowed in quantities larger than 3.4 ounces if you declare them to the TSA officer, but it is easier to pack them in containers of 3.4 ounces or smaller and avoid the conversation.

Electronics and Chargers

Laptops, tablets, e-readers, phones, cameras, and portable chargers are all allowed in carry-on bags. You will need to remove your laptop and any device larger than a tablet from your bag at security and place it in a bin for X-ray screening. Smaller electronics like phones and earbuds can stay in your bag.

Chargers and charging cables have no restrictions. Portable battery packs (power banks) are allowed, but they must be in your carry-on bag, not your checked luggage — lithium batteries can pose a fire risk in the cargo hold. If your power bank is very large or has an unusual design, take a photo and ask TSA before you pack it.

What Is Prohibited in Carry-On Luggage

Sharp objects are the most common carry-on restriction. You cannot bring knives (of any size), razors, box cutters, ice picks, or scissors with blades longer than 4 inches. Nail clippers and nail files are allowed. All of these sharp items can go in checked luggage if you need them at your destination.

Flammable items are never allowed in carry-on or checked bags. This includes lighters (with rare exceptions for one butane lighter in checked luggage only), matches, aerosol sprays, and paint thinner. Tools longer than 7 inches — hammers, wrenches, screwdrivers, saws — cannot go in carry-on bags but are allowed in checked luggage.

Firearms, ammunition, and realistic replica guns are prohibited in carry-on bags. Firearms are allowed in checked luggage only if they are unloaded, packed in a locked hard-sided container, and declared to the airline at check-in. Sporting equipment like baseball bats, golf clubs, and ski poles are prohibited in carry-on but allowed in checked bags.

Food and Beverages

Solid foods — sandwiches, fruit, cheese, crackers, cookies, chocolate — pass through security with no restrictions. You can bring a full meal in your carry-on if you want. Liquids and gels made from food, however, follow the 3-1-1 rule: peanut butter, jam, honey, yogurt, pudding, and hummus must be 3.4 ounces or smaller.

Beverages of any kind — water, juice, coffee, alcohol — cannot pass through security in your carry-on. You can buy a bottle of water or other drinks after you clear security and bring it onto the plane. If you are traveling internationally, the same rule applies: no liquids in carry-on, even if you bought them in another country.

Medications and Medical Devices

Prescription and over-the-counter medications in pill, capsule, or tablet form have no restrictions and do not need to be in your liquids bag. Medications in liquid or gel form (cough syrup, liquid ibuprofen, insulin) are allowed in reasonable quantities — you do not have to limit them to 3.4 ounces, but it is simpler to pack them that way and avoid questions at security.

Medical devices like inhalers, EpiPens, and glucose meters are allowed. If you use a CPAP machine or other medical equipment, you can bring it in your carry-on. Syringes are allowed if they are accompanied by medication or a doctor's letter explaining medical need. Thermometers containing mercury are prohibited; digital thermometers are fine.

Items That Often Surprise Travelers

Lighters are prohibited in carry-on bags, but one butane lighter is allowed in checked luggage only — not both carry-on and checked. Matches are prohibited everywhere. Candles are allowed in carry-on and checked bags. Dry ice is allowed in checked luggage only, in quantities of 2.2 pounds or less, and must be declared to the airline.

Umbrellas, walking canes, and crutches are allowed in carry-on bags if there is room, or can be checked. Sporting equipment like skis, snowboards, and surfboards must be checked. Toy guns and replica firearms that look realistic are prohibited; clearly toy-like guns are allowed. Fireworks and sparklers are never allowed in either carry-on or checked bags.

Lithium batteries (the kind in electronics) are allowed in carry-on bags as part of your devices. Spare lithium batteries are prohibited in carry-on but allowed in checked luggage in limited quantities — usually up to two spares per battery type. If you are traveling with unusual electronics or batteries, contact your airline before you pack.

Frequently Asked Questions

Can I bring a lighter or matches on a plane?

Lighters are prohibited in carry-on bags. One butane lighter is allowed in checked luggage only. Matches are prohibited in both carry-on and checked bags. If you smoke and need a lighter at your destination, buy one after you arrive.

What if my deodorant or sunscreen is larger than 3.4 ounces?

If it is a gel, cream, or spray, it must be 3.4 ounces or smaller for carry-on. Solid deodorant sticks do not count as a liquid and can be any size. For larger quantities of sunscreen or lotion, pack them in checked luggage instead, or buy travel-sized containers.

Can I bring my laptop through security without removing it?

No. Laptops and tablets larger than a standard tablet must be removed from your bag and placed in a bin for X-ray screening. Some newer airports have advanced screening machines that allow laptops to stay in bags, but you should assume you will need to remove it.

Are protein powder and baby formula allowed in carry-on bags?

Yes. Powder substances like protein powder, baby formula, and flour are allowed in carry-on bags in any quantity. TSA may open the container and test it at security, so pack it where you can access it easily. If you are traveling with baby formula, you do not need to declare it, but having it easily accessible speeds up screening.

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

Yes. Chargers and cables have no restrictions. Power banks (portable battery packs) must go in your carry-on bag, not checked luggage, because lithium batteries pose a fire risk in the cargo hold. Bring your charger in your carry-on so you can charge devices during layovers.