You can bring liquids on a plane in containers of 3.4 ounces (100 milliliters) or less each. All these containers must fit into one clear, quart-sized (about 1 liter) zip-top bag. You are allowed only one such bag per passenger in your carry-on luggage. This is known as the TSA 3-1-1 liquids rule: 3.4 ounces per container, 1 quart-sized bag, and 1 bag per passenger

. There is no strict limit on the number of 3.4-ounce containers you can bring, as long as they all fit within the quart-sized bag. Typically, this means about seven to nine containers, depending on their shape and size

. Exceptions exist for medically necessary liquids (like prescription medications, baby formula, breast milk), which can be carried in larger quantities but must be declared and presented for inspection

. Liquids purchased after passing through security (such as duty-free items) are also exempt from these size restrictions if kept in sealed, original packaging with a receipt

. In summary:

• Maximum container size: 3.4 ounces (100 ml)
• All containers must fit in one quart-sized clear bag
• One bag per passenger allowed in carry-on
• No fixed limit on number of containers, just what fits in the bag
• Exceptions for medications, baby food, and duty-free liquids

This rule applies to liquids, gels, creams, pastes, and aerosols you carry through security checkpoints