Research The Rules
Right when you book your flight the next thing you should do is research the baggage carry on allowance and size restrictions. A pink suitcase like the on above definitely is too big for carry on and even the backpack might be a bit cumbersome under the seat. Most US based airlines allow a carry-on of 22 x 14 x 9 inches while British Airways gives you a little extra at 22 x 18 x 10 inches. Both allow a personal item that is meant to be stored under your seat.
The space under your seat varies by type of plane and it will cut into your overall comfort if you fill it. British Airways actually specifies the size of this bag as 16 x 12 x 6 inches, unless you’re traveling from Brazil then you get more room. Proof it’s worth checking with every trip. Knowing the airline rules means no surprises when you get to your gate and no need to fear that little metal measuring cage!