Nothing slows a security line down quite like a carry-on that has to be searched for a forgotten full-size shampoo. The good news: the TSA liquids rule is simple once you know exactly what it says, and packing around it takes about five minutes.
What the TSA 3-1-1 liquids rule actually says
According to the TSA's official 3-1-1 liquids rule, liquids, gels, and aerosols in your carry-on have to be in containers of 3.4 ounces (100 milliliters) or less, and they all need to fit in one quart-size bag. Each passenger is limited to one bag.
- 3.4 oz (100 ml) or less per container
- 1 quart-size bag for all of them
- 1 bag per passenger
The 3-1-1 limits apply to carry-on bags, so full-size bottles can travel in a checked bag instead. TSA also has separate guidance for items like medications and baby formula, so check with TSA directly before you fly if either applies to you.
What counts as a liquid at airport security
A good rule of thumb: if it pours, pumps, sprays, or spreads, pack it as a liquid. For most travelers, that includes:
- Shampoo, conditioner, and body wash
- Lotion, moisturizer, and sunscreen
- Toothpaste and mouthwash
- Liquid foundation, serums, and hair gel
- Aerosol deodorant, hairspray, and dry shampoo
Solid items — a toothbrush, floss, bar soap, a solid stick deodorant, or a shampoo bar — don't need to go in the liquids bag, which frees up room for the things that do.
An easy mistake: container size, not how much is left
The 3.4-ounce limit applies to the container, not to what's inside it. A half-used 8 oz bottle of shampoo is still an 8 oz bottle, so it won't clear the carry-on rule. Decanting into properly sized bottles is the reliable fix.
How to pack carry-on toiletries so security goes smoothly
- Decant into refillable travel bottles. Bottles sized well under the 3.4 oz limit take the guesswork out.
- Label everything. Shampoo and conditioner look identical in a travel bottle, and a quick label saves a guessing game in the shower.
- Leave a little room at the top. Bottles filled to the brim are harder to seal fully, and cabin pressure changes can push liquid past a cap that isn't closed tight.
- Keep every liquid in one clear quart-size bag. Then keep that bag with the rest of your toiletries. Berth, our hanging toiletry bag, has a clear bottom pouch that keeps liquids apart from everything else, so they're easy to find when your security lane asks for them.
- Pack the liquids bag near the top of your carry-on. Digging to the bottom of a full bag at the checkpoint is what really holds things up.
Disposable travel-size bottles vs. refillable travel bottles
Buying travel-size minis before every trip works, but the cost adds up, you're limited to whatever the store carries, and the empties usually end up in a hotel trash can. Refillable travel bottles take a few minutes to fill at home, let you bring the products you already use, and last for trip after trip. If you travel more than a couple of times a year, refillables are usually the better long-term choice.
TSA liquids checklist before you leave for the airport
- Every liquid, gel, and aerosol is in a container of 3.4 oz (100 ml) or less
- All of them fit in one quart-size bag that closes
- Bottles are labeled and capped tight, with a little headroom
- The liquids bag is packed where you can reach it quickly
- Anything full-size is in your checked bag
Keep reading
Next, see our guide on how to pack a toiletry bag for travel, or learn how to organize cables and chargers for travel. You can also browse our travel organizers or check the FAQ.