Do you know the TSA 3-1-1 rule ? If you also have a question about how many ounces can you take on a plane , Take one quart-size plastic bag and put any liquid-based, essential toiletries inside of it. All liquids (including gels like toothpaste) and a few types of food that are classified as liquids must be kept in separate containers that are no larger than 3.4 ounces. You must remove them from your suitcase and place them in a bin to be X-rayed and occasionally further examined when you pass through the airport security check. If you have any prohibited items, you should throw them away or return to the gate to check them; otherwise, your helpful TSA agent will seize them.