How to Pack Liquids in a Carry-On (TSA 3-1-1 Rule)

TSA's 3-1-1 rule requires that every liquid, gel, aerosol, cream, and paste in your carry-on be 3.4 ounces (100ml) or smaller per container, all fitting inside one clear, quart-sized zip-top bag, with one bag per passenger. The rule applies to shampoo, conditioner, toothpaste, sunscreen, perfume, face wash, lotion, and any other substance that isn't a solid. Knowing exactly what counts as a liquid — and what doesn't — lets you pack smarter: a few solid-form product swaps can free up most of your quart bag for the items that actually need to be liquid.

What Exactly Counts as a Liquid Under TSA Rules

TSA defines liquids broadly: anything that can flow, spread, or be squeezed out of a container is subject to the 3-1-1 rule. This includes gels (hair gel, aloe vera gel), aerosols (dry shampoo, hairspray, spray sunscreen), creams (moisturizers, face creams), pastes (toothpaste), and lotions. If you're unsure whether something qualifies, apply the simple test: if it pours, pumps, squeezes, or sprays, it's a liquid under TSA rules.

Liquids: shampoo, conditioner, face wash, body wash, mouthwash, contact lens solution
Gels: hair gel, hand sanitizer, aloe vera, teeth-whitening gel
Aerosols: hairspray, dry shampoo, spray-on sunscreen, spray deodorant
Pastes: toothpaste, foundation, tinted moisturizer
Lotions and creams: moisturizer, sunscreen lotion, SPF foundation

What Does NOT Count as a Liquid

Solid-form products are not subject to the 3-1-1 rule and can go directly into your bag without the quart-size limit. This is the most important distinction for frequent travelers — each solid swap frees up one slot in your quart bag.

Solid bar soap: not a liquid — no size limit
Solid deodorant (stick or crystal): not a liquid — no size limit
Toothpaste tablets (Bite, Archie's): not a liquid — no size limit
Solid shampoo/conditioner bars (Lush): not a liquid — no size limit
Solid sunscreen sticks (Supergoop Unseen Sunscreen Stick): not a liquid — no size limit
Powder makeup (pressed powder, eyeshadow, blush): not a liquid
Mascara: technically a liquid, but enforcement is inconsistent — use 3.4oz or smaller to be safe

How the 3-1-1 Quart Bag Rule Works in Practice

Your quart bag is roughly 7 x 8 inches — a standard 1-quart zip-lock freezer bag meets the requirement, as does any clear, resealable toiletry bag of similar size. All bottles must fit inside with the bag sealed; a bulging bag that won't close flat may be pulled for additional screening. TSA does not specify a maximum number of bottles, just that they must all fit inside the one quart bag.

Use a clear, zip-top bag — you must be able to seal it
Approximate capacity: 6–9 travel-size bottles depending on size
One bag per passenger — a family of 4 gets 4 quart bags
Remove the quart bag from your carry-on and place it in a separate bin at screening
Refillable silicone bottles (GoToob, Humangear GoBites) can replace single-use travel sizes

Medical and Infant Exceptions

Medications over 3.4oz are allowed in carry-on bags in reasonable quantities — TSA explicitly exempts medically necessary liquids from the 3-1-1 rule. You do not need to fit medications in your quart bag, but you must declare them to the TSA officer at the checkpoint. Similarly, breast milk, infant formula, and juice for infants and toddlers are allowed in quantities exceeding 3.4oz and do not need to fit in the quart bag.

Medications: allowed over 3.4oz — declare separately at security, keep in original labeled containers
Insulin and other injectable medications: always carry on; never check (see our medication packing guide)
Breast milk/formula: allowed in 'reasonable quantities' — typically up to 24oz per container is accepted without issue
Liquid nutrition supplements: allowed if medically necessary — declare them
Eye drops: technically a liquid; for non-prescription drops under 3.4oz, just pack in your quart bag

The Best Solid Swaps to Free Up Your Quart Bag

Switching even two or three products to solid alternatives can eliminate most of your liquids-bag stress. The best swaps are for the highest-volume items — shampoo, conditioner, and toothpaste together typically eat up half a quart bag.

Shampoo bar (Lush Shampoo Bar, HiBar): replaces a 3.4oz shampoo bottle; lasts 50–80 washes
Conditioner bar (Lush Conditioner Bar): replaces a 3.4oz conditioner bottle
Toothpaste tablets (Bite, Archie's): replaces the bulkiest item in most quart bags
Solid sunscreen stick (Supergoop, Sun Bum): replaces a 3.4oz tube; most go up to SPF 50
Solid deodorant: any standard stick — no quart bag space needed
Sheet masks (dry): replace liquid face masks
Solid perfume (Kiehl's, LUSH): replaces a perfume bottle

Tips for Getting Through Security Faster

Packing your quart bag in the top of your carry-on — not buried at the bottom — is the single biggest time-saver at security. TSA requires you to remove the bag and place it in a bin, and digging through a packed bag wastes 30–60 seconds and often leads to re-screening.

Pack the quart bag in the outer pocket of your carry-on for instant removal
Remove the bag before you reach the bin area — have it in hand as you approach
If you have TSA PreCheck, you do NOT need to remove your quart bag — it can stay in your bag
Freeze water in a reusable bottle before your flight — frozen water is not subject to liquid rules; it must be completely solid at the checkpoint
Don't pack duty-free liquids over 3.4oz in your carry-on unless they're sealed in a STEB (security-tamper evident bag) with a receipt

Frequently Asked Questions

Is toothpaste considered a liquid by TSA?

Yes, toothpaste is classified as a paste under TSA's 3-1-1 rule and must be 3.4oz (100ml) or smaller to go in a carry-on. Standard travel-size toothpaste tubes are 0.85oz to 3oz and comply with the rule. To avoid using a slot in your quart bag, switch to toothpaste tablets (Bite or Archie's) — they are classified as a solid.

Does deodorant count as a liquid for carry-on?

It depends on the form: solid stick deodorant is not a liquid and has no size restriction in carry-on. Gel, spray, roll-on, and cream deodorants are subject to the 3-1-1 rule and must be 3.4oz or smaller. When in doubt, switch to a solid stick to eliminate the question entirely.

Can I bring a full-size shampoo in my checked bag?

Yes, the 3-1-1 rule only applies to carry-on bags. In checked luggage you can bring liquids of any size, subject only to the airline's weight limit. Aerosols in checked bags have a separate limit: no single container larger than 18oz and no more than 70oz total per passenger for non-medicated aerosols.

What if my liquids bag doesn't close because it's too full?

TSA requires the bag to seal. If it won't close, you have too much — either consolidate into fewer bottles, transfer products into smaller refillable containers, or move non-critical items to your checked bag. Airport security will ask you to remove items until the bag seals.

Are protein powder and supplements considered liquids?

Dry powder supplements are not liquids and are not subject to the 3-1-1 rule in carry-on. However, powders over 12oz (350ml) in carry-on may be asked to be placed in a separate bin for additional screening. Pre-mixed liquid protein shakes are subject to the 3-1-1 rule.

Can I bring wine or alcohol in my carry-on?

You can bring alcohol in containers of 3.4oz or smaller in your quart bag. For larger quantities, alcohol between 24–70% ABV can go in checked bags up to 5 liters per person. Duty-free alcohol purchased after security can be brought on board in a sealed STEB bag with a receipt, but may be confiscated at international connecting airports.

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