Size: (LxWxH) 28 x 23 x 16cm(Approx)/11" height x 9" bottom width x 6" bottom thickness
One zippered back pocket: 5" x 4", big enough to fit standard size smart phone; There are 3 pockets inside of the backpack: One zippered side pocket (6.5" width x 4" deep), two open-top pockets (4.5" x 3.5" and 4" x 3.5"). Adjustable strap Length: 37" fully extended, 21" Shortened
Top opening is expandable with the 2 side zipper and it's approximately 12.5" wide with side zippers unzipped or 9" wide with side zippers zipped.
It is quite roomy and plenty of space to carry all you daily essentials. It is advertised as a girl's schoolbag however it is stylish and roomy enough for various ages. There is room inside for a couple books, but not a big notebook. I do think you could put an small tablet, a few necessities, and a wallet