18 inches x 14 inches x 4 - 5 inches OUTSIDE - rear strap to go over suitcase handle. Two front pockets, three rear pockets. INSIDE - place for ID card, moveable bulkhead and strap to secure laptop. Place for power cord. Four pouches of various sizes. *The outside front was 'loved' by one of our cats, so it's a little roughed up. But the integrity of the bag is solid.