Storage Unit Size Calculator
Determine what size storage unit you need based on furniture and box inventory. Enter values for instant results with step-by-step formulas.
Reviewed for accuracy by Daniel Agrici, Founder & Lead Developer
Storage Unit Size Calculator
Calculator
Adjust values & calculateEnter your values below. Every result is computed in your browser — no data is sent to any server.
Formula: Required Volume = Total Item Volume / Packing Efficiency (0.70)
Additional inputs: Large (6 cu ft).
Worked example — A 5x10 storage unit is recommended, estimated at approximately $85/month.
Formula
Required Volume = Total Item Volume / Packing Efficiency (0.70)
Where Total Item Volume is the sum of cubic feet for all furniture, appliances, and boxes, and Packing Efficiency accounts for wasted space due to irregular shapes, access aisles, and stacking limitations. The calculator then matches the required volume to the smallest standard storage unit that fits.
Worked Examples
Example 1: One-Bedroom Apartment Storage
Problem:You need to store: 1 queen bed, 1 sofa, 1 dresser, 1 table, 2 chairs, 10 small boxes, 5 medium boxes, and 3 large boxes.
Solution:Bed: 70 cu ft | Sofa: 60 cu ft | Dresser: 30 cu ft | Table: 25 cu ft 2 chairs: 20 cu ft | 10 small boxes: 15 cu ft | 5 medium boxes: 15 cu ft | 3 large boxes: 18 cu ft Total volume: 253 cu ft With 70% packing efficiency: 253 / 0.70 = 361 cu ft needed Recommended unit: 5x10 (400 cu ft capacity)
Result:A 5x10 storage unit is recommended, estimated at approximately $85/month.
Example 2: Three-Bedroom House Storage
Problem:Store 3 beds, 2 sofas, 4 dressers, 2 tables, 8 chairs, 2 large appliances, 20 small boxes, 15 medium boxes, and 10 large boxes.
Solution:3 beds: 210 cu ft | 2 sofas: 120 cu ft | 4 dressers: 120 cu ft | 2 tables: 50 cu ft 8 chairs: 80 cu ft | 2 appliances: 80 cu ft | 20 small: 30 cu ft | 15 medium: 45 cu ft | 10 large: 60 cu ft Total volume: 795 cu ft With 70% packing efficiency: 795 / 0.70 = 1,136 cu ft needed Recommended unit: 10x15 (1,200 cu ft capacity)
Result:A 10x15 storage unit is recommended, estimated at approximately $175/month.
Frequently Asked Questions
What size storage unit do I need for a one-bedroom apartment?
A one-bedroom apartment typically requires a 5x10 or 10x10 storage unit depending on how much furniture you have. A 5x10 unit provides 50 square feet and about 400 cubic feet of usable space, which is usually enough for a bed, a small sofa, a dresser, a table, and about 15 to 20 boxes. If you have a larger sofa, multiple dressers, or several appliances, you should step up to a 10x10 unit with 100 square feet and 800 cubic feet. The rule of thumb is that a 5x10 handles a studio or small one-bedroom, while a 10x10 is better for a fully furnished one-bedroom apartment.
How is storage unit size measured and priced?
Storage units are measured by their floor dimensions in feet, such as 5x5, 5x10, 10x10, 10x15, and 10x20. The ceiling height is typically 8 feet, so a 10x10 unit has 800 cubic feet of total volume. Pricing varies by location, climate control, and unit size, but generally ranges from $50 per month for a 5x5 unit to $300 or more for a 10x30 unit. Climate-controlled units cost 25 to 50 percent more than standard units. Urban areas tend to charge higher rates than suburban or rural locations. Many facilities offer first-month-free promotions and discounts for prepaying several months in advance.
Should I get a climate-controlled storage unit?
Climate-controlled storage units maintain temperatures between 55 and 80 degrees Fahrenheit and regulate humidity levels. You should choose climate control if you are storing wooden furniture, leather goods, electronics, musical instruments, photographs, artwork, or important documents. Extreme heat and cold can warp wood, crack leather, damage electronic components, and cause mold growth on paper and fabric. If you live in an area with hot summers, cold winters, or high humidity, climate control is strongly recommended for long-term storage exceeding three months. The extra cost of 25 to 50 percent is usually worthwhile to protect valuable belongings from temperature and moisture damage.
How do I maximize space in my storage unit?
Start by placing the largest and heaviest items against the back wall first, such as sofas stood on end, mattresses, and large appliances. Disassemble furniture like bed frames, tables, and bookshelves to save significant space. Stack boxes from heaviest on the bottom to lightest on top, and create a center aisle so you can access items in the back without moving everything. Use uniform box sizes when possible for easier stacking. Fill dresser drawers, appliances like washers and dryers, and any hollow spaces with smaller items and linens. Place frequently needed items near the front door of the unit for easy access without disturbing everything else.
What items should not be stored in a storage unit?
Most storage facilities prohibit perishable food, plants, live animals, flammable liquids like gasoline and propane, hazardous materials, explosives, and illegal items. You should also avoid storing irreplaceable items like birth certificates, passports, and original legal documents unless the facility has excellent security and climate control. Medications, batteries, and aerosol cans can be damaged by temperature extremes and should generally be avoided. Wet or damp items should never be placed in storage as they will promote mold and mildew growth that can spread to other belongings. Check your specific facility agreement for their complete list of prohibited items.
How does the packing efficiency factor work in Storage Unit Size Calculator?
The packing efficiency factor accounts for the reality that you cannot use 100 percent of a storage unit volume. Storage Unit Size Calculator uses a 70 percent packing efficiency, meaning you can effectively use about 70 percent of the total cubic footage. The remaining 30 percent is lost to irregular item shapes, gaps between furniture, walkway space needed to access items, and the inability to stack items perfectly to the ceiling. Professional movers can sometimes achieve 75 to 80 percent efficiency, but for most people doing their own packing, 65 to 70 percent is realistic. This factor prevents you from choosing a unit that is too small and ending up needing to upgrade.
Is it cheaper to rent a bigger unit or two smaller units?
Renting one larger unit is almost always cheaper than renting two smaller units. For example, a single 10x20 unit typically costs $200 to $250 per month, while two 10x10 units would cost $260 to $300 per month. Beyond cost savings, a single larger unit is more convenient because all your items are in one location, you only need one lock, and you have more flexibility in how you arrange items. However, if you need to access certain items frequently while keeping others in long-term storage, two units can be practical. Some facilities offer multi-unit discounts, so always ask about pricing for both options before deciding.
How long can I store items in a storage unit?
Most storage facilities offer month-to-month leases with no maximum time limit, so you can store items indefinitely as long as you continue paying rent. However, for long-term storage exceeding six months, you should take extra precautions to protect your belongings. Use moisture absorbers or desiccant packets in boxes, cover furniture with breathable cotton sheets rather than plastic which traps moisture, and visit the unit periodically to check for any issues. Some items deteriorate over time regardless of storage conditions, including mattresses which may develop dust mites and certain fabrics that can yellow. The average storage rental duration is about 14 months according to industry data.
What insurance do I need for stored items?
Most storage facilities require tenants to carry insurance on stored items, either through the facility tenant protection plan or your own policy. Check your homeowners or renters insurance first, as many policies cover items in storage up to a certain percentage of your total coverage, typically 10 percent. If your existing policy does not cover storage or the coverage is insufficient, storage facility insurance typically costs $10 to $30 per month for $2,000 to $5,000 in coverage. Document everything you store with photographs and a detailed inventory list before placing items in the unit. Keep this inventory and your insurance documentation outside the storage unit so you can access it if you need to file a claim.
How do I estimate volume for oddly shaped items?
For irregular items, measure the length, width, and height of the smallest box that would contain the item, then multiply those three measurements in feet to get the cubic footage. For example, a bicycle might be 6 feet long, 2 feet wide, and 3.5 feet tall, giving it a volume footprint of 42 cubic feet even though the bike itself is much smaller. This bounding box method is accurate for storage planning because you cannot typically nest other items inside the gaps of irregular shapes. For collections of small items, estimate how many standard boxes they would fill and use box volumes instead. When in doubt, round up to the next standard box size to ensure your estimates are conservative enough.
References
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Reviewed for accuracy by Daniel Agrici, Founder & Lead Developer · Editorial policy
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