The 3.4-ounce limit per container, 1 quart bag total

TSA allows you to bring liquids, gels, and aerosols through security in containers of 3.4 ounces (100 millilitres) or smaller. All containers must fit inside a single clear plastic bag that holds about 1 quart total — roughly the size of a sandwich bag. You get one bag per person.

This rule applies to carry-on luggage only. Checked baggage has no liquid restrictions, so you can pack full-size bottles there without limits.

The 3.4-ounce limit is per container, not per type of liquid. You can bring multiple 3.4-ounce bottles of different products — shampoo, lotion, toothpaste, cologne — as long as they all fit in the quart bag.

Key Takeaways

  • Each liquid container can hold no more than 3.4 ounces; anything larger must go in checked baggage.
  • All containers together must fit inside one clear quart-sized plastic bag, which TSA will inspect at security.
  • Liquids include shampoo, lotion, toothpaste, sunscreen, cologne, deodorant, peanut butter, and yogurt — anything that flows or spreads.
  • You can bring the same liquid in multiple small containers as long as each one is 3.4 ounces or less.
  • Checked baggage has no ounce limit for liquids, so full-size bottles go in your suitcase, not your carry-on.

What counts as a liquid under TSA rules

TSA defines liquids broadly. The category includes obvious ones — water, juice, shampoo, conditioner, lotion, sunscreen, cologne, perfume — but also things that may surprise you: toothpaste, deodorant, peanut butter, yogurt, honey, jam, and creamy sauces. If it flows, spreads, or would spill if the container tipped over, TSA treats it as a liquid.

Solid foods like cheese, chocolate bars, and crackers are not liquids and have no ounce limit in carry-on. Frozen items are allowed if they are completely solid when you go through security, though TSA may hold them for inspection.

Medications and medical devices have different rules. Prescription medications in liquid or gel form can exceed 3.4 ounces if you declare them and keep them separate from your quart bag. Insulin, for example, does not count toward the 3.4-ounce limit.

How to pack your liquids bag for security

Use a clear plastic bag about the size of a quart (roughly 7 by 8 inches). You can buy TSA-approved bags at airports or drugstores, or use any clear plastic bag that size. Place all your liquid containers inside, seal it, and have it ready before you reach the security line.

At the checkpoint, remove the bag from your carry-on and place it in the bin with your shoes and belt. TSA will scan it separately. You do not need to remove individual containers unless an officer asks.

Containers do not have to be full. A 3.4-ounce bottle that is half empty still counts as a 3.4-ounce container for packing purposes — you cannot bring two half-full bottles and claim they equal one container.

Ounces versus millilitres on the label

TSA uses 100 millilitres as the limit, which equals 3.4 fluid ounces. Most travel-size products sold in stores are labeled in millilitres. Look for "100 ml" or smaller on the label.

If a label shows only ounces, 3.4 fl oz is the maximum. Some products list both: "100 ml / 3.4 fl oz". Either measurement on the label tells you whether the container is within the limit.

Do not estimate by eye. A container that looks small might be 5 ounces. Check the printed label on the bottom or back of the bottle.

What happens if you bring oversized containers

TSA officers will catch oversized liquid containers at the security checkpoint. You will have to choose: throw the container away, go back to check it in your suitcase (if you have time), or leave it behind. You cannot bring it through security.

This happens most often with full-size deodorant, sunscreen, or shampoo bottles. Many travelers do not realize these count as liquids. If you are traveling with products you use daily, buy travel sizes before your trip or pack them in checked luggage.

Duty-free and international flights

Liquids you buy in a duty-free shop after passing through security can be larger than 3.4 ounces. You can bring them on the plane in a sealed duty-free bag. However, if you are connecting to another flight, TSA may confiscate duty-free liquids at your connection unless they are in a sealed bag with a receipt showing the purchase was made that day.

For international flights departing the United States, the 3.4-ounce rule still applies to your carry-on. Some countries have different rules for flights leaving their airports, but TSA rules govern what you can bring through U.S. security.

Travel-size products and where to find them

Most drugstores, supermarkets, and travel retailers sell 3.4-ounce or smaller versions of common products: shampoo, conditioner, lotion, toothpaste, deodorant, and sunscreen. These are labeled "travel size" or "TSA-approved" and cost more per ounce than full-size bottles, but they solve the packing problem.

Airport shops also carry travel-size liquids, though prices are higher. If you forget to pack small bottles, you can buy them after you clear security.

Some products — like prescription medications or specialty items — may not come in travel sizes. For those, pack them in checked baggage or contact the manufacturer to ask about smaller versions.

Frequently Asked Questions

Can I bring a full water bottle through security?

No. Water is a liquid and must follow the 3.4-ounce rule. You can bring an empty water bottle through security and fill it at a fountain or water station after you clear the checkpoint. Many airports have refill stations near gates.

Do I need to remove my liquids bag if I have TSA PreCheck?

TSA PreCheck members do not have to remove shoes, belts, or light jackets, but liquids bags still must come out of carry-on luggage and go in the bin. The rule is the same for all passengers.

What if my container says 100 ml but looks bigger than 3.4 ounces?

Trust the label, not your eye. TSA officers check the printed measurement on the container. If the label says 100 ml or 3.4 fl oz, it meets the rule, even if it appears larger.

Can I bring baby formula or breast milk through security?

Yes. Baby formula, breast milk, and juice for infants or toddlers are exempt from the 3.4-ounce limit. You do not need to put them in your quart bag. Declare them to the officer at security and keep them separate from other liquids.

Do solid deodorants count as liquids?

Solid stick deodorant does not count as a liquid. Gel, cream, or spray deodorant does. Check the product type on the label. If you are unsure, pack it in checked baggage to avoid delays at security.