Was curious how tight the regulations are for a carry on at the airports? What is the correct size of backpack I need to get to make sure that I don't have to check it in when I get there. How rigid are these restrictions? Don't want any surprises as our group is going 'no check-ins'. Thanks for the help!!
You'll need to check with each of the carriers you will be traveling on. They will have the information posted on their websites. Many of the foreign carriers will also have a weight requirement as well.
General rule of thumb is 22x14x9 although you will need to check.
Sharon, Ron is right. For example, the value airlines are more strict.
I'd call the airlines or visit their site for dimensions. If its around the size of a normal carry on (20 inch), you'll be fine.