Carry-on luggage must fit under airplane seats or in storage bins. Accordingly, there are size restrictions. Carry-on bags generally cannot be larger than 45 linear inches. Linear inches are calculated by adding the bag's height, width and depth measurements. The number of bags a traveler may carry on varies depending on the airline, and in some cases airlines may require passengers to check all bags. Airlines typically allow travelers also to carry on at least one personal item, such as a purse or briefcase.
Passengers must adhere to the Transportation Security Administration 3-1-1 rule for carry-on luggage. According to the rule, liquid items in carry-on bags must be in bottles that are 3.4 ounces or smaller. Travelers must combine all bottles containing liquid in one quart-sized, clear, plastic, zip-lock bag. This enables security officers to more quickly examine your liquids. Passengers are limited to one such plastic bag.
There are exceptions to the 3-1-1 rule. Medications, baby formula and food, and breast milk are allowed in reasonable quantities larger than 3 ounces. Additionally, it is not necessary to place these items in a plastic bag. However, you must submit the items for inspection at the security checkpoint.
Several items are prohibited from inclusion in carry-on luggage. TSA provides a comprehensive list of such items on its website. Some of these items include: box cutters, knives (excluding plastic or round-blade butter knives), razor-type blades, pool cues, lacrosse sticks, realistic replicas of firearms, gel candles and hammers.
While not permitted in carry-on luggage, passengers can pack some of these items in checked bags. However, passengers must sheath or securely wrap sharp items to prevent injury to baggage inspectors and handlers. Scissors with a blade measuring less than 4 inches are permitted in carry-on luggage.
