The 3-1-1 carry-on rule limits liquids to 3.4-oz containers inside one quart-size bag, with one bag per traveler at screening.
Confusion at the checkpoint wastes time and can cost you toiletries. This guide spells out the liquid size limit, what counts as a liquid, and the edge cases that trip up flyers. You’ll get plain rules, smart packing moves, and clear exceptions that keep your bag moving.
Carry-On 3-1-1 Rule: What Counts And What Doesn’t
The basics are simple: any liquid, gel, aerosol, cream, or paste in your cabin bag must be in containers of 3.4 ounces (100 mL) or less. All of those small containers must fit in a single, clear, zip-top quart bag. One bag per person. The rule covers shampoo, lotion, sunscreen, hair gel, deodorant sticks that smear, mascara, liquid makeup, lip gloss, toothpaste, and similar goos.
Some items feel dry but act like liquids at screening. Peanut butter, hummus, soft cheese, and spreadable foods count as gels. Snow globes count if the globe holds more than a splash. If it pours, smears, pumps, or spreads, treat it as liquid and size it for the small bag.
Early Decision Table: What Fits The Quart Bag
Use this quick table to sort common items long before you zip your suitcase.
| Item | Carry-On Rule | Tip |
|---|---|---|
| Shampoo, conditioner, body wash | ≤ 3.4 oz each; in quart bag | Buy travel minis or refill from full-size |
| Toothpaste, mouthwash | ≤ 3.4 oz; in quart bag | Solid toothpaste tabs skip the bag |
| Makeup (liquid/cream), mascara, lip gloss | ≤ 3.4 oz; in quart bag | Powder or solid sticks ride outside |
| Deodorant | Stick outside; gel/spray in bag ≤ 3.4 oz | Pick a solid for more space |
| Foods that smear (peanut butter, dips) | ≤ 3.4 oz; in quart bag | Pack crackers; buy the spread after security |
| Snow globes | Only tiny globes tethered to base | Most go in checked bags |
| Disposable razors | Allowed in cabin | Keep blades covered |
| Medically needed liquids | Reasonable amounts allowed | Declare for separate screening |
| Baby milk, formula, toddler drinks | Reasonable amounts allowed | Tell the officer; extra screening applies |
| Duty-free liquids | Allowed when sealed in STEB | Keep receipt; don’t open the bag |
Why This Rule Exists And How Officers Apply It
Screeners use the size limit to control risk from liquid threats while keeping lines moving. CT scanners and other tools help them read inside your bag, but the liquid limit still applies in the U.S. A tidy quart pouch helps them clear you faster.
Keep a spare zip-top bag in your suitcase; if the first one tears, you won’t scramble at the belt. Clear bags help officers see contents at a glance, which trims questions and keeps the line flowing for everyone.
Packing Tactics That Save Space And Stress
Swap Liquids For Solids
Solid formats dodge the limits and free room in the pouch. Bar shampoo and conditioner, solid cologne, stick sunscreen, and hard perfume samples pack small and ride outside the quart bag.
Right-Size Your Bottles
Most trips don’t need a full mini. Refill 1-ounce leak-proof bottles and label them. Squeeze the air out before capping. Place bottles inside a zip pouch to catch drips. Keep the pouch near the top of your bag for a quick grab at screening.
Group By Use, Not Brand
Think in routines: morning wash, sunscreen, makeup basics, night cleanse. Build tiny kits with just what you use. Skip “just in case” liquids; you can buy many items at the destination.
Edge Cases: What Trips Up Travelers
Aerosols And Sprays
Travel-size hairspray, dry shampoo, shaving cream, and deodorant spray count as liquids. Keep each can at 3.4 ounces or less and place them in the quart bag. Oversized cans belong in checked luggage. Some flammables are restricted by airlines in checked bags; read your carrier’s page if you fly with big spray cans.
Powders In Cabin Bags
Large amounts of powder can draw extra screening. Keep powder containers small in hand luggage or move bulk protein or drink mixes to checked bags. Baby formula and similar items are treated with care, yet officers may still need a closer look.
Duty-Free Purchases On Connections
Liquor or perfume bought after security can ride on board when sealed in a tamper-evident bag with the receipt. Problems start during layovers if the seal breaks. Keep the package closed until you reach your final stop.
Medically Necessary Liquids And Baby Needs
Items needed for health, baby feeding, or special diets don’t have to fit inside the quart bag. Reasonable quantities are allowed. Declare them at the start of screening and place them in a separate bin when asked. Officers may swab the containers. Pack them so you can lift them out fast.
Make The Conversation Smooth
Speak up early: “I have liquid meds and baby milk.” Keep prescriptions or doctor’s notes handy if you have them. While not required, they help if a label is unclear. Ice packs and gel packs used to keep items cool can fly in a semi-frozen state.
Electronics, Batteries, And The Liquids Bag
Power banks and spare lithium batteries are never allowed in checked baggage and must ride in the cabin. Tape over exposed terminals or use sleeves to prevent short circuits. Keep cameras and drones with removable batteries in carry-on, with spares stored individually. Many checkpoints with CT scanners let you leave small items inside the bag, yet officers can ask you to remove them.
Carry-On Liquids Rule: Clarity From Official Sources
For the rule text and examples, see the TSA liquids page. For battery limits that apply across airlines, review the FAA battery guidance. Policies can change with equipment upgrades, but the U.S. liquid size limit still applies at most checkpoints.
Step-By-Step: Getting Through Screening Fast
Before You Pack
- List daily liquids you actually use; skip duplicates.
- Move anything bulky to your checked bag or plan to buy on arrival.
- Refill small bottles and label them with a marker.
- Swap to solid bars or sticks where you can.
Night Before The Flight
- Place all small liquid containers in the clear quart pouch.
- Stage the pouch at the top of your cabin bag.
- Charge electronics; store spare batteries in sleeves.
- Pre-sort food: liquids or gels in the pouch, solid snacks outside.
At The Checkpoint
- Pull the quart bag and place it in a bin when asked.
- Tell the officer if you carry liquid meds or baby items.
- Keep electronics neat; follow local bin instructions.
Close Variant Guide: Hand Luggage Liquid Rule With Examples
This section gathers common gray areas and gives a simple ruling so you can decide fast while packing.
Toiletries And Personal Care
Face wash, toner, setting spray, liquid foundation, nail polish, and cuticle oil belong in the pouch. Makeup remover wipes ride outside. Safety razors with cartridges are fine; straight razors don’t pass. Perfume samples under 3.4 ounces are fine in the pouch; solid perfume sits outside.
Food And Drinks Brought From Home
Soups, stews, sauces, and smoothies count as liquids and don’t pass the size limit. Jelly, jam, and honey also count. Hard cheese, sandwiches, cookies, and whole fruit are fine. Peanut butter cups under the size limit can sit in the pouch; a full jar belongs in checked luggage.
Sports, Camps, And Special Diets
Protein shakes, liquid nutrition, and gel energy packs fall under the liquid rule unless carried for medical reasons. If you need them for health, pack what you need for the travel window and declare them. Powder drink mix can ride in the cabin, yet large containers can draw a closer look.
Second Table: Liquid Types And Quick Rulings
| Liquid Type | Carry-On Ruling | Notes |
|---|---|---|
| Toiletry liquids, gels, creams | ≤ 3.4 oz each; in quart bag | Refill small bottles; label them |
| Medications and medical liquids | Allowed in needed amounts | Declare; expect quick swab test |
| Baby milk, formula, toddler drinks | Allowed in needed amounts | Tell the officer; cooling packs allowed |
| Duty-free alcohol and perfume | Allowed when sealed with receipt | Keep sealed during connections |
| Aerosol toiletries (small cans) | ≤ 3.4 oz; in quart bag | Large cans ride in checked luggage |
| Spreadable foods (jams, dips) | ≤ 3.4 oz; in quart bag | Buy larger sizes after security |
| Powders and mixes | Allowed; extra screening possible | Pack big tubs in checked bags |
| Spare lithium batteries | Carry-on only | Cover terminals; follow Wh limits |
Quick Checklist Before You Leave Home
- All liquid items at 3.4 ounces or less and inside the quart pouch.
- Medically needed liquids and baby items packed together and easy to show.
- Power banks and spare batteries in the cabin bag, not in checked luggage.
- Any big liquid buys planned for after security or at the destination.
- Print this list or save it to your phone.
Common Clarifications For Travelers
Lipstick
Solid lipstick rides outside the pouch. Liquid gloss goes inside the pouch and must meet the size limit.
Refillable Water Bottles
Bring it empty through screening, then fill at a fountain or cafe after the checkpoint.
If You’re Stopped For A Liquid
Stay calm and choose: toss it, check the bag, or step out and return after moving the item to checked luggage.
Pack Smart And Breeze Through
Keep liquids small, keep the pouch handy, and speak up early about medical or baby items. Stick to solids where you can. With this setup, you’ll pass the belt with less stress and land with everything you meant to bring.