Every carry-on traveler needs to know the quart-sized bag for flights rule: TSA requires all liquids, gels, and aerosols to fit in a single clear zip-top bag roughly one quart in size, with each container at 3.4 oz (100ml) or less. One bag per person. The bag does not have to be a Ziploc brand. Any clear, resealable bag of approximately that size works. If you have TSA PreCheck, you do not even need to take it out at the checkpoint.
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What Size Is a Quart-Sized Bag?
A quart is roughly one liter. The standard Ziploc quart bag measures about 7 x 8 inches. TSA does not specify an exact dimension for the bag itself. The rule is that it must be quart-sized, clear, and resealable. In practice, anything in the 6×9 to 7×8 inch range passes without issue.
You do not need to buy Ziploc specifically. Any clear zip-lock bag from any brand works. Some travelers use reusable silicone bags, which are fine as long as they are clear and seal shut. Frosted or opaque bags get flagged. Bags without a zip closure (like produce bags) also get flagged.
The Full TSA 3-1-1 Rule
The shorthand is 3-1-1:
- 3.4 oz (100ml) or less per container
- 1 quart-sized clear zip-top bag per passenger
- 1 bag only. You do not get two.
The limit is on the container size, not the amount of liquid in it. A 6oz shampoo bottle that is half empty does not pass. The container itself must be 3.4 oz or smaller. TSA agents check the label, not the fill level.
At security, the bag comes out of your carry-on and goes in the bin separately. That is the other reason it needs to be clear. Agents need to see the containers without opening it. If you have TSA PreCheck, the bag stays in your bag. See our full breakdown of what the 100ml liquid rule covers for the complete list of what counts as a liquid.
What Fits in a Quart Bag
A standard quart bag holds roughly 8 to 10 travel-sized containers depending on their shape. A realistic carry-on toiletry set might look like:
- Travel shampoo (2 oz)
- Travel conditioner (2 oz)
- Travel body wash (2 oz)
- Toothpaste (100ml tube)
- Face moisturizer (1 oz)
- Sunscreen (3 oz)
- Small perfume or cologne (travel size)
That is a full toiletry kit and it fits. The quart bag fills up fast though. Adding a full-size deodorant spray, contact lens solution, and a few other items quickly gets you to the limit. For trips longer than 3 to 4 days, most people either buy toiletries at the destination or check a bag.
How to Pack Your Quart Bag Efficiently
A few things that actually make a difference:
- Use travel-sized containers, not full sizes decanted into smaller bottles. GoToob and Muji bottles are worth buying if you travel regularly. They seal better than cheap alternatives and do not leak in your bag.
- Pack the quart bag last and store it in an outer pocket. When you get to security, it needs to come out fast. Digging through your main compartment is the main cause of checkpoint slowdowns.
- Do not overfill it. A bag crammed so full it will not seal properly will get flagged. The seal needs to close completely.
- Consider what you can skip. Solid shampoo bars, solid conditioner, and solid deodorant do not count as liquids and do not go in the bag at all. Using even one or two solid alternatives frees up significant space.
Exemptions: What Does Not Need to Go in the Bag
Several categories of liquids are exempt from the quart bag rule:
- Prescription liquid medications: declare them separately at the checkpoint
- Baby formula, breast milk, and toddler food: exempt in reasonable quantities, declared separately
- Duty-free liquids purchased after the security checkpoint: allowed in the sealed duty-free bag with receipt
Solid items like stick deodorant, lip balm, powder makeup, and solid shampoo bars never need to go in the bag regardless of size. Only liquids, gels, creams, pastes, and aerosols fall under the rule. For a full breakdown of what counts, see our guide to TSA security rules.
Quart-Sized Bag for Flights: Frequently Asked Questions
Does the bag have to be a Ziploc brand?
No. Any clear, resealable bag of approximately quart size works. It needs to be see-through and have a zip-style closure. Frosted bags, produce bags, and bags without proper closures get flagged. Generic store-brand zip bags are fine.
Can I bring two quart-sized bags?
No. TSA allows one quart-sized bag per passenger. If you try to bring two, one will be confiscated or you will be asked to consolidate. If you have more liquids than fit in one bag, the excess needs to go in your checked luggage.
What exactly is 3.4 oz in milliliters?
3.4 oz equals 100 milliliters. Most travel-sized toiletry containers sold in the US are labeled in both measurements. The limit is on the container size, not how much liquid is actually in it. A half-empty 6oz bottle still does not pass.
Do I have to take the quart bag out at airport security?
Yes, unless you have TSA PreCheck. Standard screening requires the bag to come out of your carry-on and go in the bin separately so agents can see the containers. With TSA PreCheck, it stays in your bag.
Can I use a reusable silicone bag instead of a plastic Ziploc?
Yes, as long as it is clear and seals completely. Frosted silicone bags do not work because agents cannot see through them. Clear silicone zip bags are fine and hold up better over time than disposable plastic ones.
Does toothpaste go in the quart bag?
Yes. Toothpaste is a paste and counts as a liquid under TSA rules. A standard 100ml tube is exactly at the limit. Anything larger goes in checked baggage or gets left behind.