Recently, major airlines including American, Delta, and United have adopted new maximum dimensions for their carry-on baggage allowances. The industry standard used to be 22in x 15in x 9in, but those have recently shrunk, according to George Hobica, founder of Airfarewatchdog.
Being messaged as a new ‘FAA’ regulation, the new dimensions have shrunk to 22in x 14in x 9in. The difference? One inch. Not all airlines have adopted these new restrictions, though.
Carry-on allowance for most other airlines can be found here, or on the airline’s own website.