Though the rule is two carry-on items per flight, there are some exceptions and limitations to this stipulation---mostly as it refers to size. Airlines allow one bag and one personal item, such as a purse, laptop or coat. However, this rule is not enforced absolutely. Generally speaking, passengers can carry a purse, general carry-on bag and a jacket onboard with ease. Other items allowed above the two-item limitation include books, diaper bags, therapeutic oxygen provided by the airline and assistive devices, such as wheelchairs, canes, walkers and CPAP devices. These exceptions are not required to adhere to either the quantity, size or weight limitations imposed on other carry-on items. Passengers may find that when these items prove to be bulky or heavy, such as is the case with a stroller or car seat, they can be transported to the gate and checked in there for convenience. Delta Air Lines also allows one box or bag of duty free merchandise as an exception to the carry-on quantity limitations. Contact your airline carrier for more specific details.
Carry-on bags, in keeping with the limitations of an overhead bin or space underneath an airline seat, should generally be no more than 45 inches, when combining the length, width and height. Some airlines, such as American, place more restrictive measures on the second carry-on item, limiting its combined length, width and height to 36 inches. Items larger than this will not fit under a seat, and may be subject to check-in upon discovery.
Carry-on luggage and personal items are subject to weight limitations. Generally speaking, 40 lbs. is the maximum that an item may weight, unless they are among the items listed as exceptions. While some airlines, such as Delta, don't specify a weight restriction, they reserve the right to impose additional restrictions at the time of departure, providing size and space limitations make this necessary. Any item refused because of size or weight must be checked in, and if found to exceed checked luggage restrictions, additional fees will be imposed.
