A carry-on bag can hold clothes, electronics, approved toiletries, medicines, and valuables, subject to liquid and safety limits.
One full-size shampoo bottle can trigger a bag search, while the power bank many travelers place in checked luggage belongs in the cabin. For flights screened at US airports, what you can carry in a carry-on bag comes down to three filters: Transportation Security Administration rules, Federal Aviation Administration battery rules, and your airline’s baggage limits.
Most clothes, solid snacks, personal electronics, documents, medication, and travel-size toiletries are allowed. Sharp objects, oversized liquids, weapons, and hazardous materials face tighter controls, and some items cannot fly at all.
What Fits In A Carry-On Bag?
A carry-on bag may contain most ordinary personal belongings as long as each item passes security rules and the packed bag fits the airline’s limit. The safest default is to keep valuables, documents, medicines, electronics, and anything needed during the flight with you.
- Clothing, shoes, books, and travel documents
- Phones, laptops, tablets, cameras, and charging cables
- Solid food such as sandwiches, fruit, crackers, and candy
- Travel-size toiletries packed under the liquids rule
- Prescription and over-the-counter medicine
- Jewelry, cash, house keys, and other valuables
TSA decides whether an item can pass the checkpoint. The airline decides whether the bag is small and light enough for the cabin.
Carry-On Size Comes From The Airline
Airlines set carry-on dimensions, weight limits, and fare restrictions, so a bag accepted by one carrier may be rejected by another. A size near 22 by 14 by 9 inches is common on large US airlines, but handles and wheels count and the limit is not universal.
Some low-fare tickets include only a personal item that fits under the seat. Many international carriers also weigh cabin bags at check-in or the gate. Check the operating airline for every segment, especially on codeshare trips where the airline named on the ticket is not the airline flying the plane.
Carry-On Bag Rules: What Fits And What Does Not
Most everyday items are allowed, but liquids, blades, batteries, and alcohol have specific limits. The table below covers the rules that cause the most packing mistakes.
| Item Category | Carry-On Status | Rule That Applies |
|---|---|---|
| Clothes and shoes | Allowed | No TSA quantity limit; the packed bag must meet airline limits. |
| Solid food and snacks | Allowed | Solid food can pass screening; spreads and pourable foods follow the liquids rule. |
| Liquids, gels, and aerosols | Limited | Each container must hold 3.4 ounces or 100 milliliters or less and fit in one quart-size bag. |
| Medically necessary liquids | Allowed with screening | Reasonable quantities above 3.4 ounces are permitted; tell the officer and separate them for screening. |
| Formula, breast milk, and toddler drinks | Allowed with screening | Reasonable quantities above 3.4 ounces are permitted and do not need to fit in the quart-size bag. |
| Laptops, tablets, and cameras | Allowed | Devices may need to come out of the bag and may need to power on if requested. |
| Power banks and spare lithium batteries | Carry-on only | Up to 100 Wh is normally allowed; 101 to 160 Wh needs airline approval, with no more than two spares. |
| Disposable razors | Allowed | Disposable and cartridge razors are allowed; loose safety-razor blades are not. |
| Scissors | Limited | Blades must be shorter than 4 inches when measured from the pivot point. |
| Alcohol | Limited | Mini bottles must be 3.4 ounces or less and fit inside the single quart-size liquids bag. |
For an unusual object, TSA’s complete What Can I Bring list shows whether it belongs in carry-on baggage, checked baggage, both, or neither. The final decision at the checkpoint rests with the TSA officer.
Liquids, Medicines, And Food Need Different Treatment
The standard liquids rule allows one quart-size bag per passenger, filled with containers no larger than 3.4 ounces or 100 milliliters each. The container’s labeled capacity controls the decision, so a half-empty 6-ounce bottle does not qualify.
Liquids include more than drinks. Toothpaste, lotion, sunscreen, perfume, shampoo, peanut butter, yogurt, jam, salsa, and similar spreads or gels count. An empty reusable water bottle can pass screening and be filled after the checkpoint.
Medically necessary liquids, formula, breast milk, toddler drinks, and baby food can exceed the normal limit in reasonable quantities for the trip. Tell the officer before screening and keep these items easy to remove because they may need separate inspection.
TSA permission does not override customs or agricultural import rules at the destination, so fresh produce, meat, and other foods may still be restricted after arrival.
Which Items Must Stay In The Cabin?
Power banks, spare lithium batteries, electronic cigarettes, and vaping devices must remain in the passenger cabin rather than checked baggage. If a carry-on is taken at the gate, remove these items before handing over the bag.
The Federal Aviation Administration allows most spare lithium-ion batteries up to 100 watt-hours without airline approval. Batteries from 101 to 160 watt-hours need airline approval and are limited to two spares; batteries above 160 watt-hours are not allowed on passenger aircraft. Protect exposed terminals with the original packaging, terminal caps, tape, or separate plastic bags.
Damaged, defective, or recalled lithium batteries must not travel. Keep phones, laptops, cameras, and other battery devices protected from accidental activation and physical damage.
What To Leave Out Or Move To Checked Baggage
Knives, box cutters, loose razor blades, large scissors, clubs, bats, and many long tools should stay out of the cabin. Some may travel in checked baggage when packed safely, while explosives and many hazardous materials are forbidden everywhere on the aircraft.
- Move to checked baggage: full-size toiletries, most knives, tools longer than 7 inches, baseball bats, golf clubs, and similar sporting equipment.
- Use formal airline procedures: unloaded firearms and ammunition may be accepted only in checked baggage under strict declaration and packing rules.
- Leave at home: fireworks, flares, fuel, spray paint, alcohol above 70% ABV, and damaged lithium batteries.
Rules can differ outside the United States. On an international trip, satisfy the airline and every security authority on the itinerary, including the return airport and any connecting country.
Pack For Easier Screening
A layered bag with restricted items separated near the top is easier to inspect and less likely to be unpacked at the checkpoint. Start with an empty bag so forgotten knives, tools, or ammunition cannot remain in a side pocket.
- Check the airline’s cabin-bag size, weight, and fare allowance.
- Place travel documents, valuables, medicines, and fragile electronics in the cabin bag.
- Put liquids in one clear quart-size bag and keep it near the top.
- Keep large electronics accessible in case the screening lane requires removal.
- Protect power-bank and spare-battery terminals from short circuits.
- Check any unusual food, tool, sporting item, or medical device before leaving home.
Gate-check warning: Remove power banks, spare lithium batteries, electronic cigarettes, medicines, documents, and valuables before a carry-on bag goes into the cargo hold.
The Carry-On Packing Decision
Carry an item when TSA permits it, the airline accepts the bag, and the item is valuable, fragile, battery-powered, medically needed, or useful during the flight. Move an item to checked baggage when it is permitted there but fails the cabin rule.
- Carry it: clothes, solid snacks, travel documents, medicine, electronics, power banks, valuables, and compliant toiletries.
- Check it: full-size liquids, most sharp objects, long tools, and cabin-prohibited sporting equipment that the airline accepts.
- Do not pack it: explosives, fuel, forbidden hazardous materials, and damaged or recalled batteries.
- Confirm before departure: oversized batteries, mobility equipment, unusual medical supplies, dry ice, and any item not clearly listed by TSA or the airline.
The stricter rule wins when TSA, an airline, or a foreign security authority sets different limits. A five-minute item check before leaving home is far easier than surrendering property or repacking at the airport.
References & Sources
- Transportation Security Administration.“What Can I Bring? Complete List.”Lists current carry-on and checked-baggage rules for common items screened at US airports.