Interior of CS3: 13.5" tall, 10.0" wide, 3.0 inches deep. (34cm x 25cm x 7.6cm)
Interior of CS4: 13.5" tall, 10.0" wide, 4.0 inches deep. (34cm x 25cm x 10.2cm)
Exterior of entire bag: 14" tall, 13" wide, 10.5" deep. (36cm x 33cm x 27cm) (Including side pockets)

Keep in mind that the bag material is flexible, so the size of the interior storage may be able to "stretch" out just a bit in one direction or another. Also keep in mind that over-stuffing your bag can cause seam or material failure, and this is not covered by warranty.