The International Air Transport Association (IATA) proposed a new maximum size limit for carry-on baggage on airlines. The IATA proposes a limit of 55cm x 35cm x 20 cm (22 x 14 x 8 inches) with a volume of 38,500 cm3, which is 39 percent - or four soccer balls - smaller than the previous IATA standard, reported Quartz.

The previous limit was 56cm x 45cm x 25 cm.

The reduction is a result of the "IATA Cabin OK" program that seeks to certify certain luggage to meet the requirements of IATA.

Tom Windmuller, an IATA executive, said that it intends to guarantee flyers that their bags will be allowed on board. It also aims to improve airline performance since the boarding time will be reduced.

Airlines aren't obligated to adopt the new policy, but Windmuller said that about "30 or 40" airlines are willing to apply the policy.

Windmuller said that many airlines have different size requirements for carry-ons, which can lead to confusion and that the new standard size is the "perfect size," according to Business Insider. 

The proposed baggage size is smaller than the current limits on American Airlines, Delta, United, Southwest, British Airways, EasyJet, Lufthansa, Air France and Emirates. 

Meanwhile, EasyJet and British Airways still allow carry-ons as large as the old standard for economy class passengers.

To make sure that your bags are small enough for the plane, you can buy an "IATA Cabin OK" certified bag.