My 4-year-old son uses this backpack Monday through Friday at preschool. It's used mostly for carrying his stuffed puppy dog and some art work but once in a while we will pack a change of clothes inside. It's plenty big and fits him well enough but the edges of the bag are starting to show wear and tear after just a couple of months of use. Also, our son has a hard time getting his Kleen Kanteen water bottles (the smaller sippy cup size) in the side pockets. They could be a bit bigger.