My little man is almost 5 but is very tall for his age. HeŸ??s wearing a size 6/7 and a size 2 in shoes. Along with that, he is on the sever side of the Aurptism spectrum. Mentally he is closer to 18 months. Finding a size appropriate backpack with a theme he likes has been quite challenging. There were a couple prints that I let him choose between and he kept coming back to this one. I cannot say how it will hold up yet but the fit is perfect. We got the 15 inch sized bag. Ÿ???