What is the biggest size a carry on bag can be for most airlines?
The general size that most airlines allow is a carry-on with a maximum dimension of 22″ x 14″ x 9″. There are some airlines which allow up 24″ but those are very few. Some European airlines only allow a height of 20″. It’s good to check before you travel with your airlines. I have a 20″ International Upright http://www.briggs-riley.com/category/productDetail.aspx?id=20-inch-Carry-On-International-Upright_U420LC by Briggs & Riley, which has worked out well for me for both domestic and international travel. I like the Outsider handle which leaves a flat packing surface on the inside of the bag. There’s a zip-in extender panel for securely packing 1 to 2 suits. It’s just perfect for a 1 to 3 day trip on business.