Why Estimate Storage Space?

Renting a storage unit is common when moving, downsizing, or clearing seasonal items from your home. Picking a unit that's too small leads to frustration, while an oversized unit wastes money each month. Our Self Storage Unit Size Calculator helps you gauge how much space you need by considering the number of moving boxes and large furniture pieces. While every household is different, this tool provides a starting point so you can shop for storage with confidence.

Storage facilities typically offer units in standard sizes such as 5×5 feet, 5×10 feet, 10×10 feet, and larger. The ceiling height may vary, but most units are around 8 to 10 feet tall. The volume you need depends on how efficiently you pack and whether you plan to access items frequently. A little planning goes a long way toward fitting everything inside and still having room to walk if necessary.

How the Calculator Works

For simplicity, we assume each standard moving box requires about 2 cubic feet of space when stacked. Large furniture items—like couches, dressers, or mattresses—take up roughly 50 cubic feet each. Multiply the number of boxes by 2 and furniture pieces by 50, then add the results. The calculator compares the total cubic footage to common unit sizes and recommends the smallest size that fits.

For example, 20 boxes and two large furniture pieces equal 20×2 + 2×50 = 140 cubic feet. A 5×5 unit offers about 200 cubic feet (5 × 5 × 8), so it would be a snug but workable fit. If you have oddly shaped furniture or want aisle space to reach boxes in the back, consider stepping up to the next size. Many facilities allow you to upgrade later if needed, though availability can vary.

Packing Efficiently

To make the most of your storage unit, use sturdy boxes that stack well without crushing. Disassemble furniture when possible and store hardware in labeled bags. Fill drawers with lighter items to save box space, and use protective covers for mattresses and upholstered pieces. If you plan to access your belongings regularly, leave a narrow walkway down the middle of the unit. Otherwise, stack items tightly from floor to ceiling to maximize cubic footage.

Keep an inventory of what you store so you can find items later without unpacking everything. Label each box with its contents and the room it came from. Consider placing frequently used items near the front of the unit for easy retrieval. Good organization reduces the time you spend digging through piles and helps you avoid renting a larger unit than necessary.

Understanding Unit Sizes

A 5×5 unit is ideal for small loads—think a few pieces of furniture and several boxes. A 5×10 unit fits the contents of a studio apartment, while a 10×10 can handle a typical one-bedroom home. For multi-bedroom homes or vehicle storage, you may need 10×20 or larger. Climate-controlled units cost more but protect delicate items like electronics, photographs, and wooden furniture from temperature extremes and humidity.

Additional Cost and Planning Considerations

Square footage is only part of the decision. Storage companies often price units by size and location within the facility—ground-floor and drive-up units command premiums because they are easier to access. Before signing a contract, compare prices at several facilities and ask about move‑in specials, referral credits, or long‑term discounts. Some operators charge administrative fees or require you to purchase a cylinder lock and insurance on the spot. Knowing these costs upfront prevents sticker shock on move‑in day.

If you expect to store items for more than a few months, consider how your needs may change. Seasonal gear like holiday decorations and sporting equipment often accumulates over time, so leaving room for future additions can save you from upgrading to a larger unit later. Conversely, if you are storing items temporarily during a renovation or move, it may be worth selling or donating things you no longer need instead of paying to store them.

Climate Control vs. Standard Units

Standard units are essentially garages: they shield belongings from rain and sun but do little to moderate temperature or humidity. Climate‑controlled units regulate both, using insulated walls and HVAC systems to maintain a stable environment. They are recommended for wood furniture, musical instruments, artwork, photographs, electronics, and anything susceptible to mold or warping. The premium for climate control varies by region—hot, humid climates see bigger price differences—but it can be worth the cost to protect valuable or sentimental items. When comparing facilities, note whether climate‑controlled units are located indoors, which may require hauling items down hallways or using elevators.

Security and Insurance

Security features vary widely. Look for facilities with perimeter fencing, coded gate access, ample lighting, and surveillance cameras. Some high‑end facilities offer individual door alarms and on‑site staff. Even with good security, storage companies generally limit liability for lost or damaged goods, so insurance is essential. Homeowners or renters policies may cover items in storage, but coverage limits are often low. Purchasing a supplemental policy through the facility or an independent insurer ensures you are compensated in the event of theft, fire, or natural disasters.

Access, Contracts, and Fees

Access hours can range from 24/7 availability to business‑hours‑only, so verify when you can visit your unit, especially if you plan frequent drop‑offs or pickups. Month‑to‑month leases provide flexibility but may have higher rates than longer commitments. Read the contract carefully for clauses about rate increases, late fees, and notice periods for moving out. Many facilities require written notice several days before the end of the billing cycle to avoid an extra month’s charge.

Downsizing and Alternative Solutions

While storage units are convenient, they are not the only option. Decluttering, hosting a garage sale, or using digital backups for documents and photos can reduce the amount you need to store. Community centers, friends, or family might have temporary space for a few boxes, especially during short transitions like moving between apartments. For infrequently used gear such as camping equipment or tools, consider rental libraries or peer‑to‑peer lending services. Minimizing stored belongings saves money and reduces the temptation to keep items you no longer need.

Another strategy is to choose a slightly larger unit and sublet a portion to a trusted friend or family member. Splitting the cost can make a climate‑controlled, secure facility affordable while encouraging both parties to maintain an organized space. Always check the facility’s policies before subletting—some prohibit sharing access or require secondary renters to sign the lease.

Example Calculation

Let's say you have 35 boxes and three large furniture items. That's 35×2 + 3×50 = 220 cubic feet. A 5×10 unit offers around 400 cubic feet, providing enough space with room to maneuver. If your storage facility only has 10×10 units available, you'll have extra room for holiday decorations or future items.

Conclusion

Estimating your storage needs ahead of time prevents headaches and unnecessary costs. Use our calculator to gauge the right unit size for your belongings, then follow the packing tips to keep everything organized. With a little planning, you'll find a storage solution that keeps your possessions safe and accessible until you need them again.