Storage unit size guide
Storage facilities sell space by floor area, but what you actually need to know is whether your things will fit. This guide walks through the common sizes, what each one typically holds, and a simple process for choosing.
All sizes below are width by depth in feet. Most indoor units have a ceiling around 8 feet, so volume is roughly floor area times 8. Always confirm the real ceiling height with the facility before relying on it.
Size by size
| Size | Floor area | Approx. volume at 8 ft | Typically holds |
|---|---|---|---|
| 5x5 | 25 sq ft | 200 cu ft | A closet’s worth: boxes, seasonal items, a small chair |
| 5x8 | 40 sq ft | 320 cu ft | A dorm room or a small office |
| 5x10 | 50 sq ft | 400 cu ft | A studio apartment without large appliances |
| 10x10 | 100 sq ft | 800 cu ft | A one bedroom apartment |
| 10x15 | 150 sq ft | 1,200 cu ft | A two bedroom apartment |
| 10x20 | 200 sq ft | 1,600 cu ft | A two or three bedroom home, or a car |
| 10x30 | 300 sq ft | 2,400 cu ft | A four or five bedroom home |
These are starting points, not promises. A minimalist one bedroom and a fully furnished one bedroom can be a full size apart.
5x5: the walk in closet
A 5x5 suits boxes, holiday decorations, sports gear, a few small pieces of furniture, or business records. It will not take a full size mattress laid flat, and most sofas will not fit at all. Think of it as extra closet space.
5x8 and 5x10: small moves and overflow
These narrow units work for a dorm room, a studio, or furniture you are clearing out of a room. A 5x10 can usually take a twin or full mattress on edge, a dresser, a small sofa or loveseat, and a stack of boxes. The 5 foot width is the limit to watch: an 84 inch sofa is 7 feet long, so it will not lie across a 5x10. It has to go lengthwise along the 10 foot wall, and then nothing else fits beside it.
10x10: the most popular size
A 10x10 holds the contents of a typical one bedroom apartment including a queen bed, sofa, dresser, dining set, appliance and boxes. It is often the best balance of price and flexibility. Read what fits in a 10x10 for a sample layout.
10x15: two bedrooms
A 10x15 adds half again the floor space. It suits a two bedroom apartment, or a one bedroom plus a garage’s worth of tools and outdoor gear. It also gives you room for an aisle, which matters if you will need to visit.
10x20: a full home or a vehicle
A 10x20 is the size of a standard one car garage. It holds a two to three bedroom home with major appliances, or a car with a little room to spare. Check the door height and whether the unit is drive up if you plan to store a vehicle.
10x30: large homes
A 10x30 suits a four or five bedroom house, or a long term business inventory. At this size, organization matters more than space: plan aisles and keep a written inventory, or you will spend hours searching.
How to choose the right size
1. List your large items
Start with the pieces that dictate the layout: sofas, beds, dressers, tables, appliances and anything longer than 6 feet. Measure each one. Catalog dimensions are typical, and the difference of a few inches decides whether a sofa goes in sideways or not at all.
2. Count your boxes
A medium moving box is about 18 by 18 by 16 inches, roughly 3 cubic feet. Thirty medium boxes are about 90 cubic feet before you account for gaps.
3. Add it up, then add margin
Total the volume of everything and compare it to the unit’s volume. Real packing rarely exceeds about 70 percent of the space because furniture has odd shapes and you need gaps and an aisle. If your items add up to more than about 60 percent of a unit, it will feel tight. Above about 85 percent, size up.
4. Check the longest item against the narrowest wall
A unit can have plenty of volume and still fail on one dimension. A king mattress is 76 by 80 inches, a sofa can be 84 inches long, and a ladder may be 6 feet or more. Make sure every long item has a wall it fits along.
5. Lay it out
Volume math tells you whether a unit could work. A layout tells you whether it will. With the planner you can place your real items on a to scale floor plan of any unit size, stack them, and see the result in 3D. It flags anything that crosses a wall, goes through the ceiling, or would tip over.
Money saving tips
- Compare the next size up. Facilities often price sizes inconsistently, and a larger unit can occasionally cost less than a smaller one at the same site.
- Watch introductory rates. A low first month often rises sharply afterward. Compare the total cost over your expected stay.
- Climate control costs more. It is worth it for wood furniture, electronics, documents and anything sensitive to heat or humidity. It is rarely needed for garden tools.
- Downsizing beats upsizing. If you are unsure between two sizes and your stuff is flexible, plan it first rather than renting the bigger one just in case.
The bottom line
Pick the smallest unit your largest items and total volume allow, with enough margin for an aisle if you need access. Ten minutes with a tape measure and a to scale plan beats guessing. See pricing to try your layout before you sign a lease.