The 3.4-ounce rule for liquids and gels

The Transportation Security Administration (TSA) limits each liquid or gel container in your carry-on bag to 3.4 ounces (100 milliliters). This is the maximum size for a single container—not the total amount you can bring. A container larger than 3.4 ounces will be confiscated at the security checkpoint, even if it is not full.

This rule applies to the TSA and most airlines flying from U.S. airports. If you are flying internationally or from a non-U.S. airport, the limit may differ. Check your airline's website or contact them directly before you pack, since some carriers have stricter rules.

The 3.4-ounce limit exists because the TSA classifies these items as potential security risks in large quantities. A single container over the limit will hold up your security line, so measure before you pack.

Key Takeaways

  • Each liquid or gel container in your carry-on must be 3.4 ounces (100 milliliters) or smaller.
  • All containers must fit inside a single clear quart-sized plastic bag, with one bag per passenger.
  • Common items that count toward the limit include shampoo, conditioner, lotion, toothpaste, sunscreen, and liquid makeup.
  • Solid items like deodorant sticks, bar soap, and solid perfume do not count toward the liquid limit and can be any size.
  • Containers larger than 3.4 ounces will be removed at security, even if partially empty.

What counts as a liquid or gel

The TSA defines liquids and gels broadly. This includes shampoo, conditioner, body wash, lotion, sunscreen, liquid makeup, mascara, liquid eyeliner, lip gloss, toothpaste, hairspray, and perfume. Peanut butter, honey, jam, and other thick spreads also count as gels. If you are unsure whether an item is a liquid or gel, the TSA rule is straightforward: if it can be poured or spread, it counts.

Solid items do not count. Deodorant sticks, bar soap, solid perfume, lipstick, and powder makeup can be any size and do not need to go in your liquid bag. A stick of antiperspirant is fine; liquid antiperspirant is not.

How to pack liquids and gels correctly

All your liquid and gel containers must fit inside one clear quart-sized plastic bag. A quart bag is roughly 7 inches by 8 inches—the standard freezer bag size. You can buy these bags at any drugstore or supermarket, or the TSA will provide one at the checkpoint if you ask, though this slows you down.

Place each container in the bag so the TSA officer can see them without removing them. Seal the bag completely. If you are carrying multiple bags or if your bag does not seal, the TSA officer will ask you to repack at the checkpoint, which wastes time. One bag per passenger is the rule—you cannot bring two quart bags.

Measure your containers before you pack. A container that looks small might be 4 ounces. Travel-size bottles are usually safe, but check the label. If a container is larger than 3.4 ounces, buy a smaller one or pack it in checked luggage instead.

Exceptions and items you can bring full-size

Some items are exempt from the 3.4-ounce limit. Medications in liquid form (like cough syrup or insulin) can exceed 3.4 ounces, but you should declare them to the TSA officer and keep the original prescription label or pharmacy label on the bottle. Baby formula and breast milk are also exempt if you are traveling with an infant or small child.

Solid foods are not restricted by ounce limits. You can bring a full-size jar of peanut butter, a block of cheese, or a sandwich in your carry-on. The restriction applies only to liquids and gels.

What happens if you exceed the limit

If a container is larger than 3.4 ounces, the TSA officer will remove it at the security checkpoint. You will not be able to retrieve it or take it on the plane. There is no exception for nearly-empty containers—a 4-ounce bottle counts as over the limit even if it holds only a few drops.

You have two options: pack the item in checked luggage instead, or buy a travel-size version after you pass security. Many airports have shops beyond the checkpoint where you can purchase travel-size toiletries, though these are usually more expensive than buying them beforehand.

International flights and other airlines

The 3.4-ounce rule applies to flights departing from U.S. airports. If you are flying from another country, that country's aviation authority sets the rules. The European Union, Canada, Australia, and other regions have similar limits, but the exact ounce amount and bag requirements may vary.

Some airlines impose stricter rules than the TSA. Budget carriers and regional airlines sometimes limit you to smaller containers or fewer items. Check your airline's website before you pack. If you are unsure, contact the airline directly—a five-minute call saves you from losing items at security.

Frequently Asked Questions

Can I bring a full-size deodorant stick in my carry-on?

Yes. Solid deodorant sticks are not subject to the 3.4-ounce limit. Liquid or gel antiperspirant must follow the liquid rule, but a stick of solid deodorant can be any size.

Do I need to remove my liquid bag at security?

Yes. At the TSA checkpoint, remove your quart-sized bag from your carry-on and place it in the bin with your shoes and electronics. The officer will scan it separately. This is faster than waiting for them to ask you to remove it.

Can I bring toothpaste in my carry-on?

Yes, if the tube is 3.4 ounces or smaller. Most standard toothpaste tubes are around 5 to 6 ounces, so you will need to buy a travel-size tube or pack the full-size tube in checked luggage.

What if my medication is a liquid larger than 3.4 ounces?

Liquid medications are exempt from the 3.4-ounce limit. Keep the original pharmacy label on the bottle and inform the TSA officer that you are carrying medication. They may open and inspect it, but you will not have to discard it.

Can I bring an empty container larger than 3.4 ounces?

No. The TSA measures the container size, not the amount of liquid inside. An empty 5-ounce bottle will be removed at security. Fill it after you pass the checkpoint or pack it in checked luggage.