The outside of the bag measures 15x12x6 (wide). There is a flap pocket on the front, THREE main zipper compartments and one zipper pocket on the back. The two outer, main compartments can hold files and supplies. The center compartment for the laptop measures approx. 14 1/2 x 11 1/2 and has a Velcro strap to hold the laptop in place. Hope this helps! :)