How to Use the TSA 3-1-1 Liquids Rule Checker
The TSA's "3-1-1" rule governs which liquids, gels, and aerosols you can bring through security in your carry-on bag. Forgetting this rule is one of the most common reasons travelers get stopped at the checkpoint and have to surrender full-size shampoo bottles or lotions. This checker lets you enter your container size and how many you're packing, then tells you instantly whether your carry-on liquids meet the rule.
The rule has two parts, and both must be true at once. First, each individual container must hold 3.4 ounces (100 ml) or less โ this is based on the container's labeled capacity, not how much liquid is actually left inside it. Second, all of your liquid containers combined must fit inside a single quart-size, clear, resealable plastic bag, and TSA allows only one such bag per passenger.
Larger containers, even if mostly empty, will be confiscated at the checkpoint unless they go in checked luggage instead. Exceptions exist for medically necessary liquids and baby formula in reasonable quantities beyond 3.4 oz, but these must be declared to the TSA officer separately and are subject to additional screening.
Frequently Asked Questions
Containers larger than 3.4 oz (100 ml) must go in checked baggage or be purchased after security, even if they're not full โ the limit applies to the container's size, not how much liquid is inside.
TSA allows one quart-size, clear, resealable bag per passenger. Anything that doesn't fit must be checked or left behind โ you can't use a second bag to carry the overflow.