Working with airline members of IATA and aircraft manufacturers, an optimum size guideline for carry-on bags has been agreed that will make the best use of cabin storage space. A size of 55 x 35 x 20 cm (or 21.5 x 13.5 x 7.5 inches) means that theoretically everyone should have a chance to store their carry-on bags on board aircraft of 120 seats or larger.

Working with airline members of IATA and aircraft manufacturers, an optimum size guideline for carry-on bags has been agreed that will make the best use of cabin storage space. A size of 55 x 35 x 20 cm (or 21.5 x 13.5 x 7.5 inches) means that theoretically everyone should have a chance to store their carry-on bags on board aircraft of 120 seats or larger.

The International Air Transport Association suggests a new optimal carry on side of 21.5 inches tall, by 13.5 inches wide, and 7.5 inches deep. That’s smaller than the current maximum size which is 22 inches by 14 inches by 9 inches.

The guideline is an effort to free up space in the overhead bins.

“Everybody likes what they have and it’s working out as it is,” said Jane Ross, a frequent flier.

Airline officials say the guidelines help ensure all passengers can fit their bag in an overhead compartment, but Chris Chmura sees it another way. “They collected almost $2.6 billion in bag fees last year alone I imagine that’s not enough,” he said.

“The development of an agreed optimal cabin bag size will bring common sense and order to the problem of differing sizes for carry-on bags. We know the current situation can be frustrating for passengers. This work will help to iron out inconsistencies and lead to an improved passenger experience,” said Tom Windmuller, IATA’s Senior Vice President for Airport, Passenger, Cargo and Security.

So far only international airlines have signed on to these new restrictions, but U.S. airlines may do so.