What Size Storage Unit Do I Need? A Room-by-Room Guide

A studio fits a 5x10, a two-bedroom home fits a 10x15 and a three-bedroom home fits a 10x20, according to the size guides the two largest US operators publish for their own units. The number that decides it is not your box count but the floor area your furniture takes up, because boxes stack to the ceiling and sofas do not.

The standard sizes below come from Public Storage’s and CubeSmart’s own guides, mapped to the box counts from our packing box calculator.

The standard sizes and what they hold

Floor areas are the unit’s nominal dimensions; the volume column is floor area times the 8-foot ceiling CubeSmart says most units have (10 × 10 × 8 = 800 cubic feet), which both operators quote.

Unit	Floor area	Volume at 8 ft	Large boxes (Public Storage)	Home size, per the operators	Our box-calculator match
5x5	25 sq ft	200 cu ft	Up to 10	One closet (Public Storage); a small walk-in closet (CubeSmart)	Overflow only
5x10	50 sq ft	400 cu ft	20 or more	A studio apartment (Public Storage)	Studio, about 27 boxes
5x15	75 sq ft	600 cu ft	Around 30	A large bedroom (Public Storage)	Studio with more furniture
10x10	100 sq ft	800 cu ft	Around 40	Two small bedrooms (Public Storage); a 1-bedroom apartment (CubeSmart)	1 bedroom
10x15	150 sq ft	1,200 cu ft	Around 60	A two-bedroom home (Public Storage); a two-bedroom apartment (CubeSmart)	2 bedrooms, about 61 boxes
10x20	200 sq ft	1,600 cu ft	Around 80	A three-bedroom home (Public Storage); 2 to 3 bedrooms (CubeSmart)	3 bedrooms
10x25	250 sq ft	2,000 cu ft	Not stated	A four-bedroom home (Public Storage)	4 bedrooms
10x30	300 sq ft	2,400 cu ft	Not stated	A four- to five-bedroom house (CubeSmart)	4 bedrooms, about 120 boxes, with garage

Two cautions on reading it. The operators count large boxes only; our calculator counts a mix (for a two-bedroom home, roughly 18 small, 22 medium, 12 large, 5 wardrobe and 4 dish packs), so the totals happen to agree but the boxes are not the same shape. And “fits a two-bedroom home” assumes beds are broken down, tables have their legs off and boxes are stacked high. A unit loaded with assembled furniture and an aisle holds noticeably less.

Room by room

Studio (about 27 boxes). A 5x10 if the bed is a full or smaller and the sofa is a loveseat; Public Storage lists the unit at 20-plus large boxes and two large furniture pieces. A queen bed, a full sofa and a desk push you to a 5x15 or a 10x10.

One bedroom. A 10x10. CubeSmart lists it for a one-bedroom apartment and says it takes king mattress sets, dressers, couches and medium appliances such as a refrigerator or washer and dryer. If you are storing appliances and a sofa and a bed, this is the floor, not the ceiling.

Two bedrooms (about 61 boxes). A 10x15, on both operators’ guides. Two bedroom sets, a living room and a dining table fit if the beds and table are disassembled. A 10x20 if you also have a home office or a second sofa.

Three bedrooms. A 10x20. Public Storage matches it to a three-bedroom home at around 80 large boxes; CubeSmart lists it for two to three bedrooms and notes it can also take a motorcycle or small car. Three furnished bedrooms plus a full living and dining room is the point where people under-rent, so measure (below) rather than guess.

Four bedrooms and up (about 120 boxes). A 10x25 (Public Storage’s four-bedroom match) or a 10x30 (CubeSmart’s four- to five-bedroom match). Garage contents, patio furniture and exercise equipment are what separate the two.

Before you rent any of these, note that storing less is the cheapest size decision there is; what a pre-move clear-out saves on trucks and units is worked through in declutter before moving.

Ceiling height and stacking

Most self-storage units are 8 feet tall, per CubeSmart’s guide, and the cubic-foot figures both operators quote assume you use that height. A 10x10 is 100 square feet of floor but 800 cubic feet of space, and the difference is stacking.

Stacking well means uniform box sizes, heavy boxes at the bottom, and mattresses and table tops standing on edge against a wall rather than lying flat. It also means keeping an aisle so the back of the unit is reachable, which costs floor area; how to lay a unit out so nothing gets buried is in how to pack a storage unit. Lockers are the exception on height: Public Storage describes them as a small walk-in closet “with reduced height,” for bags, seasonal clothing and sports gear.

Climate control: what it is for

Climate control is a building, not a thermostat in your unit. CubeSmart’s definition is that it uses “reasonable efforts to maintain a temperature in the building where the storage unit is between 55 and 80 degrees Fahrenheit”; the units are “heated in the winter and cooled in the summer,” and, in its words, “not humidity controlled,” though being indoors keeps humidity closer to a house’s. Public Storage describes its climate-controlled units as designed to hold “more consistent temperature and humidity levels compared with standard units.”

What it is for, by the operators’ own lists:

• Wood furniture, which swells and warps in humidity and shrinks and cracks in cold.
• Leather, fabrics and upholstery, where mold and mildew grow in warm, humid air.
• Electronics, cameras and lenses, where the enemy is condensation.
• Photos, film, records and magnetic media, which curl, fade, warp or melt in heat.
• Musical instruments and paper documents.

If you are in a humid state along the Gulf Coast or the Southeast, or storing anything above for longer than a season, treat climate control as the default. If you are storing patio furniture, tools and plastic bins for a summer in a dry climate, a standard unit is fine. CubeSmart notes climate control is a premium feature that affects the price, so it is worth deciding on the contents, not on habit.

Drive-up or interior

A drive-up unit has a roll-up door on the outside of the building. You back the truck to the door, and there are no hallways, carts or elevators. It is the faster load and unload, which matters if you are paying movers by the hour, and it is where oversized items and vehicles go. The trade is exposure: the unit shares the outdoor temperature and dust, and it is rarely where climate control lives.

An interior unit is reached through a hallway, often by elevator, with the facility’s carts. It is slower to load but it is usually the climate-controlled option and sits behind more doors. For a long stay with anything from the climate-control list, interior wins; for a short stay of garage contents, drive-up wins.

How to measure your own load

1. List the large pieces and measure their footprints. Length times width of each bed, sofa, dresser, table and appliance. Add them up. This is the floor area the unit must have before a single box goes in.
2. Count boxes with the box calculator, then assume they stack to about shoulder height in practice, not to the ceiling.
3. Tape out the candidate unit’s footprint in the garage or on the driveway, 10 feet by 15 feet for example, and stage the large pieces inside it. If they do not fit with a path through the middle, go up a size.
4. Decide on access. If you will need the winter coats in October and the camping gear in June, you need an aisle, and an aisle is floor area.
5. Round up if in doubt. Downsizing a unit later means moving everything again; the difference between two adjacent sizes is one monthly rate, not a second move.

If the storage is a bridge between two homes rather than a long-term arrangement, the comparison with letting the mover hold the shipment is in storage-in-transit vs self storage, and the storage hub covers the rest of the process.