Estimated 10'x10' storage unit is just smaller than the size of an average spare bedroom and typically fits the contents of an entire family room or two bedrooms, including several small to medium-sized boxes. (estimated 100 square foot )

Estimated 10'x14' storage unit is about the size of a spare bedroom and typically fits the contents of three full bedrooms and larger items such as a piano, couches, tables, or large-screen TVs, plus several medium to large-sized boxes. These units work well for storing the contents of most standard-size homes or full apartments.
(estimated 140 square foot )

10'x20' storage unit is about the size of a one car garage and typically fits the contents of furnishings from a small house or two bedroom apartment with major appliances, many boxes and extras.
(estimated 200 square foot)