This is the largest backpack I could within the carry-on limits. I easily fit enough clothing for at least a week plus an extra pairs of shoes and toiletries, and used the side pockets for socks, undies, etc. I folded and stacked everything, layed the bag on the bed, and slid the entire stack in. This made it easy to either pull out the entire stack or just a few pieces from the stack. Together with a tote bag, this got me through 4 countries in 18 days. Using a backpack made it easier to get on and off planes, boats, and trains, as well as up and down stairs. Highly recommend.