A 5 x 5 storage unit is about the size of a closet. It fits small furnishings, TV's and several small to medium-sized boxes.
A 5 x 10 storage unit is the size of a walk-in closet. It fits furnishings of a mid-sized bedroom, including a queen-sized bed, a dresser, a TV and several small to medium-sized boxes.
A 10 x 10 storage unit is about the size of a small bedroom. It fits the contents of two full bedrooms, including several small to medium-sized boxes, and items such as mattress sets, sofas, chests of drawers, bookcases, and desks.
A 10 x 20 storage unit is about the size of a single garage stall. It fits the contents of an entire family room and two full bedrooms, including several small to medium-sized boxes.