The maximum size allowance for carry-on baggage during a WestJet flight is 21 inches by 9 inches by 15 inches and the maximum size allowance for a personal item is 16 inches by 6 inches by 13 inches, as of 2015. On WestJet flights, one carry-on bag and one personal item are allowed per person.
Some examples of the one personal item that can be brought on a flight include a laptop computer, purse or briefcase. The one carry-on bag per flight could include items such as a backpack, suitcase or kennel. Kennels have their own maximum size allowance, which is 16 inches by 17.5 inches by 8.5 inches.