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

TSA allows liquids, gels, and aerosols in containers of 3.4 ounces (100 milliliters) or smaller. All containers must fit inside a single clear plastic bag that holds about 1 quart total. This is the rule for carry-on bags at U.S. airport security checkpoints.

The limit applies to each individual container, not to the total amount of liquid you own. You can pack multiple 3.4-ounce bottles as long as they all fit in one quart-sized bag. Anything larger than 3.4 ounces in a single container will be confiscated, even if you have room in your bag.

Checked baggage has no ounce limit for most liquids, so if you need to bring larger bottles, pack them in your checked suitcase instead. The 3.4-ounce rule applies only to what you carry through security and onto the plane.

Key Takeaways

  • Each liquid container can hold no more than 3.4 ounces (100 milliliters) to pass through security.
  • All your liquid containers must fit inside one clear quart-sized plastic bag.
  • Larger bottles and full-size products belong in your checked baggage, not your carry-on.
  • The ounce limit is per container, so you can bring multiple small bottles as long as they fit in the bag.
  • TSA officers will remove any container larger than 3.4 ounces at the checkpoint.

What counts as a liquid under the 3.4-ounce rule

Liquids include obvious items like water, juice, and shampoo, but also things that may not seem liquid at first. Gels (toothpaste, hair gel), creams (moisturizer, sunscreen), pastes, and aerosols (deodorant, hairspray) all count. Peanut butter, honey, and jam are also treated as liquids by TSA.

Solid items do not count. Deodorant sticks, solid perfume, and bar soap can be any size. Powders like talc, baby powder, and protein powder are restricted differently — you can bring powder in carry-on bags, but containers larger than 12 ounces may be opened and tested at security.

If you are unsure whether something counts as a liquid, the safest approach is to pack it in your checked bag. TSA's website has a searchable tool called "What Can I Bring?" where you can type in specific items and see the rules.

How to measure and pack your containers

The 3.4-ounce limit is marked on most travel-size bottles sold in stores. If your container does not have a label, measure it yourself. 3.4 fluid ounces equals 100 milliliters — check the milliliter marking on the bottle if ounces are not shown. Many containers are labeled in both units.

TSA does not require containers to be completely full. A 3.4-ounce bottle that is half-empty still counts as a 3.4-ounce container and is allowed. You do not need to fill every bottle to the top.

Pack all your liquid containers into a clear, quart-sized plastic bag before you reach security. The bag should seal — a zip-top freezer bag works perfectly. Remove the bag from your carry-on and place it in the security bin with your shoes and electronics. You will retrieve it after your bags are screened.

What happens if a container is over 3.4 ounces

TSA officers will confiscate any single container larger than 3.4 ounces. You do not get to keep it or mail it to yourself. The item is thrown away at the checkpoint. This applies even if the bottle is mostly empty or if you have already paid for it.

If you need a full-size product for your trip, pack it in your checked suitcase instead. Checked baggage allows full-size bottles of shampoo, conditioner, lotion, and other liquids without ounce restrictions. The only limits on checked bags are weight and the airline's baggage policy.

To avoid losing items at security, review what you are packing before you leave home. Travel-size versions of most products are sold at drugstores and supermarkets for a few dollars. Buying travel sizes ahead of time is cheaper than replacing a confiscated full-size bottle.

International flights and different country rules

The 3.4-ounce rule applies to flights departing from U.S. airports, regardless of where you are flying. If you are flying from another country, that country's security rules may differ. European airports, for example, follow the same 100-milliliter (3.4-ounce) limit, but other countries may have different rules.

When you fly internationally, research the security rules for your departure airport before you pack. The International Air Transport Association (IATA) publishes guidelines, but individual countries set their own policies. Your airline's website usually lists liquid restrictions for flights from specific airports.

If you are connecting through a U.S. airport on an international trip, the 3.4-ounce rule applies to that leg. Liquids purchased in a duty-free shop after you pass security can be carried onto your next flight if it is also international, but rules vary by country and airline.

Exceptions to the 3.4-ounce rule

Certain items are exempt from the liquid rule. Medications in liquid form (including insulin and liquid vitamins) can exceed 3.4 ounces, but you should declare them to TSA. Baby formula and breast milk are also exempt and do not need to fit in the quart bag. Bring documentation if possible — a prescription label for medication or a baby's name on the formula container helps.

Duty-free liquids purchased after security screening can be carried onto your flight, even if they exceed 3.4 ounces. However, if you are connecting to another flight, the liquid must be in a sealed, tamper-evident bag provided by the duty-free shop. Some connecting airports may still confiscate it, so check your airline's policy before buying.

Frozen items are treated as solids if they are completely solid when you reach security. Ice packs and frozen gel packs are allowed. However, if they have started to thaw and are slushy or liquid, they may be confiscated.

Frequently Asked Questions

Can I bring a full water bottle if I fill it after security?

Yes. Empty water bottles are allowed through security. Many airports have water fountains and refill stations past the checkpoint. Fill your bottle after you pass security and you can bring it onto the plane.

Do I need to remove my liquids bag at security?

Yes. Remove your quart-sized bag from your carry-on and place it in the security bin along with your shoes, belt, and electronics. The TSA officer will screen it separately. You will get it back after your bags are cleared.

What if I forget about a liquid in my carry-on?

TSA will find it during screening and confiscate it if it exceeds 3.4 ounces or does not fit in your quart bag. You will not be allowed to go back and repack. Check your bag before you leave home to avoid losing items at the checkpoint.

Are there different rules for domestic and international flights?

The 3.4-ounce rule applies to all flights departing from U.S. airports, whether domestic or international. Other countries have their own rules, so check the security requirements for your departure airport if you are flying from outside the U.S.

Can I pack liquids in my checked bag without any limit?

Most liquids have no ounce limit in checked baggage. However, some hazardous materials like certain cleaning products or flammable items are restricted or banned from checked bags entirely. Check your airline's hazardous materials policy for items you are unsure about.