Carry-On Bag Restrictions to-date, International and Domestic (list)

Carry-on Bag Restrictions to-date (Smallest restrictions listed)*
- Aer Lingus Regional 48cm (18.5") x 33cm (13") x 20cm (8")
- Air France                 55cm (21") x 35cm (14") x 25cm (10")
- AirTran                     60cm (24") x 40cm (16") x 25cm (10")
- Alaska                       61cm (24") x 43cm (17") x 25cm (10")      
- British Airways         56cm (22") x 45cm (18") x 25cm (10")
- Delta                         56cm (22") x 35cm (14") x 23cm (9")
- Frontier                     60cm (24") x 40cm (16") x 25cm (10") additional charges may apply
- JetBlue                      43.2cm (17") x 33cm (13") x 27.9cm (11") under seat (overhead measurements are larger)
- RyanAir                    55cm (21") x 40cm (16") x 20cm (8")
- Southwest                 60cm (24") x 40cm (16") x 25cm (10")
- Spirit                         56cm (22") x 46cm (18") x 25cm (10") additional charges apply
- Transavia                  40cm (15") x 25cm (10") x 20cm (8") recommended size, one bag total
- United                       56cm (22") x 35cm (14") x 22cm (9")
- US Airways              56cm (22") x 36cm (14") x 23cm (9")

* cm = inches conversions may vary but are based on what is listed on each website, when in doubt, err on the smaller side

Antler Luggage has a great listing for international airlines; be sure to verify that measurements are current.