The 3.4-ounce liquid rule for carry-on bags

You can bring liquids, gels, and aerosols through TSA security in your carry-on bag only if each container holds 3.4 ounces (100 millilitres) or less. This limit applies to each individual item, not the total amount you pack. A 3.4-ounce bottle of shampoo is allowed; a 4-ounce bottle is not, even if you only fill it halfway.

All containers must fit inside a single quart-sized clear plastic bag. You remove this bag at the security checkpoint and place it in a bin. TSA officers will inspect it separately from your other carry-on items. If your bag is larger than a quart or holds more than one litre total, the entire contents will be confiscated.

This rule applies to toothpaste, deodorant, shaving cream, sunscreen, makeup, hair gel, peanut butter, yogurt, and any other substance that is liquid or gel-like at room temperature. Solid items like a bar of soap or a stick of deodorant have no ounce limit and do not need to go in the plastic bag.

Key Takeaways

  • Each liquid, gel, or aerosol container in your carry-on must be 3.4 ounces or smaller.
  • All containers must fit inside one quart-sized clear plastic bag, which you remove at security.
  • Solid items like bars of soap, solid deodorant sticks, and solid cosmetics have no ounce limit.
  • Checked baggage has no ounce limit for liquids, though some items like flammable products are still prohibited.
  • The rule applies to every liquid or gel-like substance, including food items like peanut butter and jam.

What counts as a liquid or gel under TSA rules

TSA defines a liquid as any substance that flows, pours, or spreads at room temperature. This includes obvious liquids like water, juice, and perfume, but also gels, creams, pastes, and aerosols. The key test is whether the substance would move or change shape if you tilted the container.

Common items that count as liquids include shampoo, conditioner, body wash, lotion, moisturizer, sunscreen, toothpaste, lip balm, mascara, liquid eyeliner, foundation, concealer, and nail polish. Peanut butter, honey, jam, and other spreads also count. Deodorant in a stick form does not; deodorant in a spray or roll-on does.

If you are unsure whether an item is considered a liquid, pack it in your checked bag instead. Checked baggage has no ounce limit for liquids, though certain items like paint thinner, bleach, and some cleaning products are prohibited in both carry-on and checked bags regardless of size.

Solid items with no ounce restrictions

Solid items can be any size and weight in your carry-on bag. A full-size bar of soap, a stick of solid deodorant, a bar of shampoo, or a solid perfume stick have no ounce limit. Solid cosmetics like powder, eyeshadow, blush, and bronzer are also unrestricted. You do not need to pack these in the quart-sized bag.

Food that is solid or semi-solid at room temperature is generally allowed in carry-on bags without ounce limits. A sandwich, a granola bar, a block of cheese, or a whole apple can travel with you. However, foods that are spreadable or pourable—like peanut butter, yogurt, jam, or honey—must follow the 3.4-ounce rule.

Checked baggage rules for liquids

Liquids in checked baggage have no ounce limit. You can pack full-size bottles of shampoo, lotion, perfume, or any other liquid in your checked bag without restriction. However, certain hazardous materials are prohibited in checked baggage entirely, regardless of size. These include flammable items like paint, paint thinner, lighter fluid, and some cleaning products.

Alcohol is allowed in checked baggage in quantities up to 5 litres (about 170 ounces) per passenger, but only if the alcohol content is between 24 and 70 percent by volume. Spirits above 70 percent alcohol are prohibited. Beer and wine under 24 percent alcohol have no quantity limit in checked bags.

If you are traveling with medications in liquid form, pack them in your checked bag if possible. If you must carry them on, they do not count toward the 3.4-ounce limit, but you should declare them to TSA and keep them in their original labeled containers.

How to measure and pack your liquids correctly

Check the label on each container to find the ounce measurement. It is usually printed on the bottom or back of the bottle. If the label says 3.4 ounces or less, it is allowed. If it says 3.5 ounces or more, it will not pass security. Do not estimate by eye or assume a small-looking bottle is under the limit.

Use a clear quart-sized plastic bag—the kind sold in grocery stores for food storage, or the kind TSA provides at some airports. Place all your liquid containers inside this single bag. The bag itself must close completely. If you have more liquids than fit in one quart bag, the excess will be removed at security.

Arrive at the security checkpoint with your quart bag easily accessible, not buried at the bottom of your carry-on. Remove it and place it in a bin by itself. TSA officers will scan it and may open it to inspect the contents. After security, you can return the bag to your carry-on.

International flights and different country rules

The 3.4-ounce rule applies to flights departing from the United States, including international flights. However, if you are connecting through another country or flying from a foreign airport, that country's rules may differ. Some countries have stricter limits or different definitions of what counts as a liquid.

If you are flying from Europe, Canada, Australia, or most other countries, the rule is the same: 3.4 ounces per container, all containers in one clear bag. However, some smaller airports or regional carriers may have different policies. Check with your airline or the airport's website before you travel.

Liquids purchased after you pass security—such as a bottle of water or a jar of local honey bought at an airport shop—can be brought on the plane in any quantity, because they were purchased in a find area. However, if you are connecting to another flight, you may need to repack these items depending on your next airport's rules.

What happens if you bring oversized containers to security

If a container exceeds 3.4 ounces, TSA will not allow it through the security checkpoint. The officer will confiscate it, and you will not be reimbursed. You cannot ask to pour out the excess and keep the container. The entire item will be discarded or donated.

If you have multiple containers that together exceed the quart-bag capacity, TSA will remove items until the bag meets the size requirement. You can ask the officer which items to remove, but you cannot take the removed items back through security or onto the plane.

To avoid this, measure and count your liquid containers before you leave for the airport. If you are unsure about any item, pack it in your checked bag instead. Checked bags have no ounce limit for liquids, so you can bring full-size bottles without worry.

Frequently Asked Questions

Can I bring a full-size bottle of shampoo if I only fill it halfway?

No. TSA measures the container's capacity, not how much liquid is actually inside. A 4-ounce bottle is not allowed even if it is only half full. You must use containers that are labeled 3.4 ounces or smaller.

Do solid deodorant and spray deodorant have different rules?

Yes. A solid deodorant stick has no ounce limit and does not need to go in the quart bag. Spray deodorant is an aerosol and must be 3.4 ounces or less and packed in the quart bag. Roll-on deodorant is also a liquid and follows the 3.4-ounce rule.

Can I bring toothpaste in my carry-on?

Yes, if the tube is 3.4 ounces or smaller. Most standard toothpaste tubes are 5.1 to 6.4 ounces, so they must go in checked baggage. Travel-size toothpaste tubes are usually 1 ounce and are allowed in carry-on bags.

What if I have a prescription liquid medication?

Prescription medications in liquid form do not count toward the 3.4-ounce limit. Keep them in their original labeled container and declare them to TSA at the checkpoint. You can carry them in your carry-on bag even if the container is larger than 3.4 ounces.

Can I bring alcohol in my carry-on bag?

No. Alcohol is prohibited in carry-on bags entirely, regardless of size. You can pack alcohol only in checked baggage, and only in quantities up to 5 litres per passenger if the alcohol content is between 24 and 70 percent by volume.