Especially when flying with airlines like Delta, knowing their carry-on size restrictions is crucial. Ever found yourself at the check-in counter, fingers crossed, hoping your bag fits the sizer?

Interestingly, there is no weight limit for carry-on bags as long as they follow these size metrics. If you are flying from Beijing or Shanghai, however, Delta will require the carry-on to be 22 ...

From Delta to American Airlines and even JetBlue ... most airlines also typically allow at least one free carry-on bag.

More than 15 airlines including British Airways, Delta Air Lines, Qantas, United, Virgin Atlantic and more global carriers ...