The TSA 3-1-1 Liquid Rule: 3.4 Ounces Per Container

You can bring 3.4 fluid ounces (100 milliliters) per container of liquid, gel, cream, or paste through TSA security. This is the maximum size for any single item. The rule applies to each container individually — you cannot combine smaller bottles into one larger bottle to get around the limit.

All containers must fit inside a single quart-sized clear plastic bag. One bag per passenger. If your container is larger than 3.4 ounces, it cannot go in your carry-on bag at all, even if you have room in the quart bag. You would need to pack it in checked luggage instead.

The 3.4-ounce limit has been in place since 2006 and applies to all flights departing from U.S. airports, regardless of your destination. International flights arriving in the United States follow the same rule.

Key Takeaways

  • Each liquid container can hold no more than 3.4 fluid ounces (100 milliliters) to go through security in your carry-on bag.
  • All your liquid containers must fit inside one clear quart-sized plastic bag, which you remove and place in the security bin.
  • Containers larger than 3.4 ounces are prohibited in carry-on bags but may go in checked baggage with no size limit.
  • Common liquids that count toward the limit include shampoo, conditioner, lotion, toothpaste, sunscreen, and peanut butter.

What Counts as a Liquid Under the 3-1-1 Rule

The TSA defines liquids broadly to include anything that flows, spreads, or sprays. This covers obvious items like water, juice, and cologne, but also includes products that look solid at room temperature. Peanut butter, yogurt, honey, and jam all count as liquids for TSA purposes. Deodorant, toothpaste, shaving cream, and hair gel also fall under the rule.

Solid foods like chocolate bars, granola, or a sandwich do not count as liquids and have no size restriction in carry-on bags. The difference is whether the item would spill or spread if the container tipped over. If you are unsure about a specific product, the TSA website has a "What Can I Bring?" tool where you can search by item name.

Medications and medical devices have different rules. Liquid medications in reasonable quantities for your trip are permitted in carry-on bags and do not need to fit in the quart bag. You should declare them to the security officer.

How to Pack Your Liquids for Security

Start by gathering all containers that are 3.4 ounces or smaller. Check the label on each one — the size is usually printed on the bottom or back. If a container is larger than 3.4 ounces, remove it from your carry-on and pack it in checked luggage instead.

Place all may have access to containers into a single clear quart-sized plastic bag. The bag should seal completely. You can purchase these bags at drugstores, grocery stores, or airports, or use one you already have at home — any clear, sealable plastic bag roughly the size of a quart is acceptable. Do not overstuff the bag; it should close without forcing.

When you reach the security checkpoint, remove the bag from your carry-on and place it in the security bin along with your shoes, belt, and electronics. You do not need to remove individual containers from the bag — the officer will examine it as a unit. After you pass through security, you can return the bag to your carry-on.

Common Mistakes at the Security Line

The most frequent error is bringing a container larger than 3.4 ounces in your carry-on. A full-sized bottle of shampoo, lotion, or sunscreen will be confiscated. If you need a full-sized product for your trip, pack it in checked baggage where there is no size limit.

Another common mistake is forgetting to put the quart bag in the security bin. Officers will stop you and ask you to remove it. This slows down the line and can make you late for your flight. Make the bag straightforward to access — keep it at the top of your carry-on or in an outside pocket.

Some travelers also pack liquids in the quart bag but fail to seal it, or they use a bag that is noticeably larger than a quart. While officers have some discretion, a bag that is clearly oversized may be rejected. Stick to the standard quart size to avoid delays.

Liquids in Checked Baggage Have No Size Limit

If you check a bag, you can pack full-sized bottles of shampoo, conditioner, lotion, cologne, and other liquids with no restriction on container size. There is no quart bag requirement for checked luggage. However, containers should be well-sealed to prevent leaks that could damage other items in your bag or the aircraft.

Certain hazardous liquids — such as flammable perfumes, aerosols, or cleaning products — have special rules even in checked baggage. These are rare for typical toiletries, but if you are packing something unusual, check the TSA website or call your airline before you travel.

If you are only carrying a personal item (backpack, small purse) and no checked bag, you must follow the carry-on liquid rules. Personal items are treated the same as carry-on bags for security purposes.

International Travel and Connecting Flights

The 3.4-ounce rule applies to all flights departing from U.S. airports, including international flights. If you are flying from the United States to another country, your carry-on liquids must meet the TSA limit at the U.S. checkpoint.

If you are connecting through a U.S. airport on an international journey, you will go through security again at the connection point. Any liquids you purchased after your first security screening — such as a bottle of water or lotion from an airport shop — must be 3.4 ounces or smaller, or you must pack it in checked baggage if you have one.

Some countries have their own liquid rules for flights departing their airports. These rules may be stricter or different from the TSA standard. Research your destination's regulations before you travel.

Frequently Asked Questions

Can I bring a full-sized bottle of sunscreen if I empty it to 3.4 ounces?

No. The TSA measures the container size, not the amount of product inside. A full-sized sunscreen bottle is still prohibited in carry-on bags, even if it is partially empty. You must either use a travel-sized container (3.4 ounces or smaller) or pack the full bottle in checked luggage.

Do solid deodorant and spray deodorant have the same rules?

Solid deodorant does not count as a liquid and has no size restriction in carry-on bags. Spray deodorant (aerosol) counts as a liquid and must be 3.4 ounces or smaller. Gel deodorant also counts as a liquid and must follow the 3.4-ounce limit.

What if I forget my quart bag at home?

You can purchase a quart-sized bag at the airport before you reach security, or you can ask the TSA officer if you can use a different clear plastic bag you have with you. Many airports sell travel-sized liquid bags near the security checkpoint. If you have no bag and cannot get one, you will need to remove liquids from your carry-on or check your bag instead.

Are baby formula and breast milk subject to the 3.4-ounce limit?

No. Baby formula, breast milk, and juice for infants or toddlers are exempt from the 3-1-1 rule and do not need to fit in a quart bag. You can bring reasonable quantities in carry-on bags. Declare them to the security officer so they know what you are carrying.

Can I bring multiple quart bags if I have a lot of liquids?

No. TSA rules allow one quart-sized bag per passenger. If you have more liquids than fit in one bag, the excess must go in checked luggage or be left behind. Plan ahead and use travel-sized containers to fit everything you need into one bag.