Choose Your Size: Less Than 20 sq. ft. 5' x 5', 25 sq. ft. 5' x 10', 50 sq. ft. 5' x 15', 75 sq. ft. 10' x 10', 100 sq. ft. 10' x 12', 120 sq. ft. 10' x 15', 150 sq. ft. 10' x 20', 200 sq. ft. 10' x 25', 250 sq. ft. 10' x 30', 300 sq. ft. 10' x 40', 400 sq. ft. Outside Parking Unit Size: 10' x 40', 400 sq. ft. Size Equivalent: One and a Half Car Garage File Boxes Unit Will Hold: 300 standard file boxes on shelves with access. 588 standard file boxes without shelves or aisles.