The perfect-sized bag was proposed Tuesday by the world's largest airline association, as it aims to resolve how to squeeze everyone's carry-on luggage onto a crowded plane.
The rolling suitcase would be small enough to allow every passenger on a flight of 120 people or more to fit one bag in the overhead space near their seat, said Tom Windmuller, the International Air Transport Association (IATA) senior vice president for airport, passenger, cargo and security.
Windmuller said when he compared it to his own bags, he found it was smaller than his personal carry-on but bigger than his wife's.
The precise size is 55 centimeters (21 inches) tall, 35 centimeters (13.5 inches) wide and 20 centimeters (7.5 inches) deep.
Many airlines have different size requirements for carry-ons, which can lead to confusion, said Windmuller.
"This is a nuisance for everyone," he told reporters, adding that the sizing bins many airlines place near the gates are "ridiculous."
So the IATA consulted with Boeing and Airbus to come up with the optimum size.
Then they began talking with baggage manufacturers to urge them to start making bags that fit the parameters.
Windmuller said he expected the bags to be widely available by the end of the year, and that costs would range according to the quality and materials chosen by individual luggage makers.
Those that fit the IATA size specifications would be marked with a tag, or a label, that says "IATA Cabin OK."
However, this label will only be available on new bags, and not for travelers that may already have an ideally sized bag in their collection.
Airlines are not required to sign up for the program, but Windmuller said the response from airline executives has been favorable so far.
Windmuller said the IATA has already communicated with its 260 member airlines -- who operate 83 percent of global air traffic -- about the program.