Total of four compartments:

•  Main compartment: 18" x 10" x 5" with one zipper and one mesh pocket. 
•  2nd compartment 15" x 8" x 2"
•  Front top compartment: 4" x 7" x 2.5"
•  Front bottom compartment: 10" x 8" x 2.5"
•  Hydration compatible

18" x 10" x 10"
1362 in³