TSA describes the liquids bag by capacity and by material, not by dimensions. Its Travel Checklist states the rule as 3.4 ounces or less per container, 1 quart size, clear, plastic, zip top bag (all liquids must fit in bag), 1 bag per passenger. On the pages we read on 7 September 2026, TSA published no length and width in inches for that bag anywhere. So the honest answer to "what size quart bag does TSA accept" is: one sold as a quart, clear, plastic, that zips shut with everything inside it. Every inch figure circulating online comes from somewhere other than TSA.
Last checked: 7 September 2026. These are Transportation Security Administration rules and they apply to airports in the United States. Other countries' screening authorities set their own container limits and their own bag requirements. Rules change without notice, so open tsa.gov before you fly.
What TSA Publishes About the Bag, and What It Does Not
TSA states the bag requirement at two different levels of detail on its own site, and the difference is worth seeing, because it explains most of the confusion.
| TSA page, read 7 September 2026 | How the bag is described |
|---|---|
| Liquids, Aerosols, and Gels Rule | "a quart-sized bag of liquids, aerosols, gels, creams and pastes" |
| FAQ, What is the 3-1-1 liquids rule? | "one quart-size bag of liquids, gels and aerosols" |
| Travel Checklist | "1 quart size, clear, plastic, zip top bag (all liquids must fit in bag)" |
The rule pages say quart-size and stop. The checklist adds three physical properties: clear, plastic, and zip top. None of the three pages gives a measurement. That is the whole finding, and it is why a page that hands you a confident number is telling you something TSA did not.
Our longer read of the 3-1-1 rule itself covers what each of the three numbers constrains. This page is only about the bag.
A Quart Is a Volume, So It Does Not Fix a Shape
Quart is a unit of capacity in the US customary system, equal to 32 US fluid ounces or about 0.946 liters. It says how much a container holds. It says nothing about how long or wide that container is.
For a rigid box that hardly matters. For a flexible plastic bag it matters a lot, because a bag with the same nominal capacity can be cut tall and narrow or short and wide, and can be sold with a gusseted base that expands or a flat seam that does not. Two bags can both be honestly labeled one quart and sit differently on a table.
That is the mechanism behind the complaint that starts most searches for this: mine says quart and it looks bigger than everyone else's. It probably is bigger in one direction. It is not necessarily bigger in volume.
Where the Inch Numbers Come From
Search this question and you will be given dimensions in inches, usually somewhere between six by nine and seven by eight. Those figures are published by bag manufacturers, luggage retailers and packing blogs. On the TSA pages we read, they do not appear.
We are not going to add a number to that pile, and this site's standing rule is that we do not publish a figure we have not read on the primary source. What we can tell you is what the figures are for: a retailer selling a reusable pouch needs a size to cut it to, so it picks a footprint close to a common quart storage bag and prints it. That is a manufacturing decision. It is not a threshold TSA published, and nothing about clearing a checkpoint turns on matching it exactly.
The Test That Actually Runs at the Checkpoint
Read TSA's checklist wording again and notice what it constrains: all liquids must fit in bag. The operative requirement is containment, not measurement. Nobody at the checkpoint has a ruler.
So the question your bag has to survive is practical. Does every liquid, aerosol, gel, cream and paste you are carrying sit inside it, and does it close? A bag that will not zip because a bottle is standing proud of the seam is the failure mode this rule is written to catch, and it is the one people actually hit. Buying a slightly different pouch does not fix it. Carrying less liquid does.
This is where container choice does more work than bag choice. Fewer and smaller containers is the only lever that reliably changes the outcome, and our breakdown of what fits at 1 oz, 2 oz, 3 oz and 3.4 oz covers how much product each size genuinely holds. If you are assembling from scratch, the sequence in building a travel bottle set starts from the same constraint.
"TSA-Approved" Is Not a Phrase TSA Uses About Bags
This is the second finding, and it is the more useful one commercially.
We looked for a TSA page that approves, certifies, lists or recognizes any brand or model of liquids bag, and on 7 September 2026 we did not find one. TSA does operate a recognition program for luggage locks, which is a real thing with a real published page. We found no equivalent for quart bags.
"TSA-approved quart bag" is therefore retail language. A product carrying it may be perfectly good, and a plain zip top bag from a supermarket meets the description on TSA's checklist just as well. If you already own a clear quart bag, this is one of the places where the honest answer is to buy nothing.
The one property worth paying for, if you are buying, is durability of the seal, because a reusable pouch that stops closing has failed the only test that counts.
What Happens If the Bag Is Judged Too Big
TSA prints a standing sentence on its item pages: "The final decision rests with the TSA officer on whether an item is allowed through the checkpoint." We read it on the liquid medications page, the pills page and the breast milk page on 7 September 2026.
That sentence is the reason this article promises you nothing. A bag that is visibly oversized, overstuffed or not closing invites a conversation, and how that conversation ends is the officer's call on the day, in that airport. We are not going to tell you what will happen, because we do not know and neither does anyone else writing about it.
What we can say is what the rule pages describe as the alternative for oversized liquids. TSA's liquids rule page directs items over 3.4 ounces or 100 milliliters to checked baggage. If something does not clear, that is the path it is meant to take, and it is a better plan to have made before you reach the belt than after.
Departing From an Airport Outside the United States
The quart is a US customary unit and this is a US rule. Other authorities write the same requirement in metric and shape it differently, and the bag specification is one of the parts that genuinely varies between countries, including whether a bag is required at all.
Your outbound checkpoint tells you nothing about your return one. Read the security or hand baggage page published by each departure airport's own authority, for every leg including connections, and pack to the strictest rule on the trip.
How We Checked This, and What We Left Out
We have not flown with any of this, tested any bag, or run anything through a checkpoint. This page is desk research from TSA's own pages, read on 7 September 2026.
Deliberately left out, because TSA does not publish it: any dimension in inches or centimeters for the quart bag, any tolerance for a bag slightly over quart capacity, and any list of accepted brands. Also left out is the question of which category a given product falls into, which is a separate problem covered in our read of what TSA counts as a liquid and answered per item by TSA's own What Can I Bring tool.
If you need a ruling on your specific bag before you travel, TSA runs a public help channel, AskTSA, and that is a better use of five minutes than any packing article, this one included.
FAQ
What are the official TSA quart size bag dimensions?
On the TSA pages we read on 7 September 2026, there are none. TSA describes the bag as quart size, and its Travel Checklist adds clear, plastic and zip top. No length or width in inches appears on the liquids rule page, the 3-1-1 FAQ or the checklist. Dimensions you find elsewhere come from retailers and bloggers, not from TSA.
Does the liquids bag have to be exactly one quart?
TSA states one quart-size bag per passenger and its checklist adds that all liquids must fit in the bag. It publishes no tolerance and no measurement, so there is nothing official to be exact against. The final decision rests with the TSA officer on whether an item is allowed through the checkpoint.
Is a gallon bag allowed if it is only half full?
TSA states the allowance as one quart-size bag. A gallon bag is not a quart-size bag, and fill level is not part of the published wording. We would not expect it to be treated as compliant, and we cannot promise you an outcome either way.
Do I need to buy a TSA-approved quart bag?
We found no TSA page that approves, certifies or lists any brand of liquids bag, checked 7 September 2026. TSA does run a recognition program for luggage locks; we found no equivalent for bags. A clear quart zip top bag you already own meets the description on TSA's checklist.
Does each traveler get their own quart bag?
TSA states the allowance as one bag per passenger, so travelers in their own seats each have their own. TSA's published rule pages do not address a lap infant traveling without a purchased seat, and we are not going to guess at that one. AskTSA is the place to ask.
