This Airline Is About to Shrink the Size of Carry-on Bags Allowed on Board

In a few months, Alaska Airlines passengers may have to downsize. The airline is decreasing the maximum dimensions allowed for carry-on baggage.

Beginning June 4, passengers’ carry-on items must measure 22 x 14 x 9 inches (including wheels and handles). The change is a significant decrease from current measurements of 24 x 17 x 10 inches.

Alaska explained that its current size allotment is “larger than most other international and domestic airlines allow” and that the change was made to “make sure that your carry-on bag will be accepted aboard all the flights within your itinerary.”

The airline’s reasoning is logical. Over the past few years, several other airlines have shrunk the maximum size of carry-ons allowed in the overhead compartment. In 2015, the International Air Transport Association issued guidelines that set the ideal carry-on size at 21.5 x 13.5 x 7.5 inches. Most major U.S. airlines followed these guidelines. Onboard American, Delta, JetBlue, and United, the maximum size for a carry-on is now 22 x 14 x 9 inches.

Southwest is the only airline that allows its passengers a slightly larger carry-on: 24 x 16 x 10 inches.

In its explainer, Alaska also notes that stricter carry-on dimensions will allow more passengers to store their luggage in the overhead compartments (as opposed to a gate-side check). Overhead space is an industry-wide concern.

The other method for dealing with limited overhead compartment space — implemented by American and United — is basic economy, which charges passengers for use of the overhead compartment.