What is the TSA 3-1-1 liquids rule?

The TSA 3-1-1 rule allows liquids, gels, aerosols, creams, and pastes in carry-on bags if each container is 3.4 oz (100ml) or less, all containers fit in 1 clear quart-sized zip-top bag, and each passenger is limited to 1 such bag. Full-size shampoo, conditioner, or toothpaste must go in checked baggage or be purchased after security.

What items are not allowed in a carry-on?

TSA prohibits the following in carry-on bags: liquids over 3.4 oz, firearms and ammunition (allowed in checked bags only), knives with blades over 4 inches, baseball bats, golf clubs, hockey sticks, most tools, flammable items, and lithium batteries over 100Wh (except laptops and phones). Check TSA's 'What Can I Bring?' tool for any specific item.

Can I bring food in my carry-on?

Yes. Solid food is allowed in carry-on bags with no restrictions. Liquid or gel-like foods (yogurt, soups, peanut butter, jam) are subject to the 3.4 oz limit per container. Snacks like chips, sandwiches, fruit, and candy bars are fine in any quantity. Alcohol purchased after the security checkpoint in sealed containers is allowed in carry-ons.

Can I bring a full water bottle through TSA?

Empty water bottles are allowed through security and can be filled at water fountains after the checkpoint. Full water bottles are not allowed — water is a liquid subject to the 3.4 oz rule. Exceptions: medically necessary liquids, baby formula, and breast milk in reasonable quantities are allowed with or without a baby present and do not need to fit in the quart bag.

Can I bring a laptop in my carry-on?

Yes. Laptops are allowed in carry-on bags but must be removed from the bag and placed in a separate bin during X-ray screening. This is why TSA PreCheck is particularly useful for business travelers — PreCheck lanes do not require removing laptops or liquids from bags. Lithium batteries in laptops are actually required to be in carry-on, not checked bags, due to fire risk.

What is TSA PreCheck and is it worth it?

TSA PreCheck is a trusted traveler program that provides access to expedited security lanes where you do not need to remove shoes, laptops, liquids, belts, or light jackets. It costs $78 for a 5-year membership ($15.60/year) and is accepted at 200+ US airports and 80+ airlines. PreCheck lanes typically take 5–15 minutes vs 20–45 minutes for standard. Worth it for anyone flying 3+ times per year.

TSA Carry-On Rules 2026: What You Can and Cannot Bring

The TSA 3-1-1 rule governs liquids in carry-on bags: each container must be 3.4 oz (100ml) or less, all containers must fit in one quart-sized clear zip bag, and each traveler is limited to one such bag. Solid food, laptops, phones, and most clothing have no restrictions. Firearms, knives over 4 inches, and flammable items are prohibited in carry-ons entirely. Knowing these rules before you pack means no confiscated toiletries, no gate-check surprises, and no $35–$50 last-minute checked bag fees.

The TSA screened approximately 830 million passengers in 2025. The most common reason for extra screening or item confiscation is liquids over the 3.4 oz limit — a $12 bottle of shampoo that gets thrown away at the checkpoint costs more than a travel-size replacement would have.

The 3-1-1 Liquids Rule Explained

What counts as a liquid: Anything that is liquid, gel, aerosol, cream, or paste at room temperature. This includes shampoo, conditioner, body wash, toothpaste, lotion, sunscreen, hairspray, mousse, lip gloss, mascara, foundation, and peanut butter (yes — it’s considered a gel).

What does not count as a liquid: Solid deodorant (stick form), solid makeup (powder, pressed eyeshadow), bar soap, chapstick/lip balm in solid form, solid food.

Allowed vs Prohibited: Quick Reference

What to Remove at the Checkpoint (Standard Screening)

At a standard (non-PreCheck) checkpoint, place these items in a separate bin:

Laptop (remove from bag and lay flat)
Quart bag of liquids
Shoes
Belt
Heavy jacket or coat
Any metal items from pockets

Leaving items in your bag triggers a re-scan and slows the line. Carry a small personal item bag that goes through fully empty — phones, keys, and wallet placed inside the bin reduce fumbling at the belt.

TSA PreCheck: Skip Most of the Above

TSA PreCheck lanes do not require removing shoes, laptops, liquids, belts, or light jackets. This is the primary practical advantage — most of the checkpoint delay for frequent travelers comes from the extra unpacking steps.

PreCheck details:

Cost: $78 for 5 years ($15.60/year)
Available at: 200+ US airports, 80+ airlines
Application: Online pre-enrollment, then in-person appointment (fingerprints, ID verification) — takes about 10 minutes
Wait time for approval: Typically 3–5 days after appointment

Global Entry ($100 for 5 years) includes PreCheck plus expedited CBP customs screening when returning from international travel. For anyone who travels internationally even once a year, Global Entry is the better deal. Many credit cards (Chase Sapphire Reserve, Amex Platinum, Capital One Venture X) reimburse the Global Entry or PreCheck fee entirely.

Carry-On Size Rules by Major Airline

TSA does not regulate carry-on bag size — the airlines do. Standard personal item and carry-on size limits:

Spirit, Frontier, and Allegiant charge separately for carry-on bags — the carry-on fee can be $50–$75 each way if purchased at the gate. If you’re flying these carriers, check your fare’s bag inclusion before arriving at the airport.

Packing for Carry-On Only: What Actually Works

Most travelers can fit a week’s worth of clothes plus toiletries in a 22-inch roller carry-on and a backpack personal item if they:

Use travel-size toiletries (or buy at destination for stays over 5 days)
Pack solid-form alternatives: bar shampoo, conditioner bars, solid deodorant
Use packing cubes to compress clothing
Wear the bulkiest items (shoes, jacket) on travel days
Choose quick-dry fabrics that can be hand-washed and dried overnight

The checked bag fee savings at $35–$50 per bag per direction add up to $70–$100 per trip — enough to justify buying a good carry-on bag within a few uses.

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Written by WealthVieu

WealthVieu researches and writes data-driven personal finance guides using primary sources including the IRS, Bureau of Labor Statistics, Federal Reserve, and Census Bureau.

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