Technically, there is no specific limit on the "number" of 3.4 oz (100ml) containers you can bring, as long as they all fit comfortably inside a single quart-sized, clear plastic bag. This is the TSA's "3-1-1" rule: 3.4-ounce containers, 1 bag per passenger, 1 bag per person. Most standard quart-sized bags (like a Ziploc) can hold approximately 7 to 10 travel-sized bottles depending on their shape and how you arrange them. If you can fit 15 tiny 1-oz bottles in the bag, that is also perfectly legal. The constraint is the volume of the bag itself, not the count of the items. It is important to remember that this rule applies to all liquids, gels, aerosols, creams, and pastes—including things like toothpaste, lip gloss, and peanut butter. If you have "medically necessary" liquids (like insulin or baby formula), these are exempt from the 3-1-1 rule and do not need to fit in the bag, but you must declare them to the security officer for separate screening. Any liquid containers larger than 3.4 oz must be packed in your checked luggage, regardless of how much liquid is actually inside the bottle.