Self Storage Unit Size Guide: What Fits and How to Choose

Picking a storage unit shouldn’t feel like a guessing game. Choose too small and you’re stuck playing Tetris with a sofa; too big and you’re paying for empty air. The challenge is translating real-life belongings—beds, appliances, totes, and those awkward must‑keep items—into square feet you can trust.

This guide gives you a clear, no-math headache path to the right size. We’ll start with a quick inventory, measure the bulky pieces, decide how you’ll pack and stack, then match your list to standard unit sizes with practical rules of thumb. You’ll also see when features like climate control, 24/7 access, and smartphone keyless entry (standard at Keyless Storage in Sioux City) make all the difference.

Inside, you’ll find what fits in every common size from 5×5 to 10×30, space tips for mattresses, sofas, appliances, pianos, and motorcycles, layout tricks to maximize access, side‑by‑side scenario comparisons, and a simple way to reserve your unit online. Start with Step 1: make a fast inventory of what you’ll store.

Step 1. Make an inventory of what you’ll store

Start with a fast, room‑by‑room list so nothing gets missed. Write down every large piece that won’t go in a box, then estimate how many boxes or totes you’ll have. This simple list becomes your map for sizing, packing, and choosing features in this self storage unit size guide.

• Group by room: Bedroom, living room, kitchen, garage.
• List big items: Beds, sofa, dresser, appliances, “odd shapes.”
• Estimate boxes/totes: Small, medium, large—give each a count.
• Flag fragile/valuable: For top stacking and climate control.
• Mark “access soon”: Items to keep near the front.

Step 2. Measure large items and note their orientation

Size accuracy starts with a tape measure. Capture the length, width, and height of each bulky piece and jot whether it can be disassembled or stood on end. Because typical units are about ~8 ft tall, vertical clearance is your secret weapon—choosing upright vs flat positions can shrink your footprint fast. For a quick compare, use footprint = length × width (in feet).

• Sofas: Measure the longest edge; note if it stands on end.
• Mattresses: Note size and thickness; upright orientation minimizes floor space.
• Tables/desks: Remove legs/leaves; measure the reduced footprint.
• Dressers/shelving: Measure height; plan to use as sturdy stacking bases.

Step 3. Decide how you’ll pack and stack inside the unit

Packing strategy changes the size you need. A tight, safe stack plan can turn a 10×10 wish into a 5×10 reality, while a loose pack does the opposite. Decide what goes into boxes vs. bins, what becomes a base for stacks, and how you’ll use the unit’s ~8 ft height—this self storage unit size guide assumes smart vertical use.

• Use uniform containers: Choose sturdy boxes or heavy-duty plastic bins of the same size for straighter stacks.
• Stack by weight/fragility: Put heavier boxes on the bottom and fragile items on top.
• Limit stack height: Cap stacks at four boxes; place boxes on top of sturdy furniture as platforms.
• Stage for access: Keep items you’ll need soon toward the front so you can reach them quickly.

Step 4. Estimate your volume and box count with quick rules of thumb

Now translate your list into space. First, think in cubic feet so you can compare against standard unit capacities (most storage units are about 8 ft tall). Then, turn your box list into safe, reachable stacks. This keeps your pick grounded in real numbers, not guesses.

• Use simple volume math:estimated unit volume (cu ft) ≈ unit length × unit width × 8. Compare your needs to common capacities:
  • 5×5 ≈ 200 cu ft
  • 5×10 ≈ 400 cu ft
  • 5×15 ≈ 600 cu ft
  • 10×10 ≈ 800 cu ft
  • 10×15 ≈ 1,200 cu ft
  • 10×20 ≈ 1,600 cu ft
  • 10×25 ≈ 2,000 cu ft
  • 10×30 ≈ 2,400 cu ft
• Convert your list to volume: Add rough volumes of bulky items (sofa, appliances), then check where that total lands in the list above.
• Turn boxes into stacks: Extra Space recommends stacking no more than four high. Use stacks ≈ ceiling(total boxes ÷ 4) to estimate how many floor “spots” or sturdy furniture platforms you’ll need.
• Reality check by item type: A queen or king mattress typically pushes you to 5×10 or larger; multiple bedrooms of furniture trend toward 10×10+. Add a small buffer if you want a center aisle for access.

Step 5. Choose features you need (climate control, 24/7 access, keyless entry)

Features can make or break your storage experience—and sometimes your size choice. If you’ll access often or store sensitive items, put these essentials on your checklist. At Keyless Storage in Sioux City, climate control, 24/7 access, and smartphone keyless entry come standard to keep things simple and secure.

• Climate control: Temperature- and humidity-controlled protection for electronics, wood furniture, photos, mattresses, and instruments.
• 24/7 access: Come anytime—ideal for off-hours moves, shift work, and contractors.
• Keyless entry: Secure app access; no keys to copy or lose.
• 24/7 video security: Continuous monitoring for added peace of mind.

Step 6. Standard storage unit sizes at a glance

Use this quick cheat sheet to match your list to a standard size. Most self storage units are about 8 feet tall; cubic feet below assume that height. Pick the smallest size that fits your bulky items and box stacks while leaving a little room to move.

Unit size	Square feet	Approx. cubic feet	Typical use
5×5	25	200	Storage closet; seasonal items
5×10	50	400	Studio/mid-sized bedroom
5×15	75	600	One-bedroom contents
10×10	100	800	One–two bedrooms
10×15	150	1,200	Two–three bedrooms
10×20	200	1,600	Multi-bedroom home; most cars
10×25	250	2,000	Three–four bedrooms; long items
10×30	300	2,400	Four+ bedrooms; oversized items

Step 7. What fits in a 5×5 storage unit (walk-in-closet size)

A 5×5 gives you about 25 sq ft (≈200 cu ft with ~8 ft height)—roughly a walk‑in closet. It’s ideal for decluttering a single room, seasonal gear, or student storage. With smart vertical stacking, this compact size handles more than you’d expect while keeping costs down in your self storage unit size guide plan.

• Great fits: Full/twin mattress upright, small dresser or chair, desk, bookshelf, sports gear, holiday décor, and boxes.
• Box strategy: Use uniform boxes and stack safely up to four high on sturdy bases.
• What’s tight: Queen/king mattresses (better in a 5×10), sofas, large appliances.
• Pro tip: Stand the mattress along a wall, load boxes on the dresser to free floor space.

Step 8. What fits in a 5×10 storage unit (studio or mid-sized bedroom)

A 5×10 gives you about 50 sq ft (≈400 cu ft with ~8 ft height)—the sweet spot for a studio or mid‑sized bedroom. Expect room for a queen (even king) mattress upright, a dresser, small sofa or loveseat, TV, and several boxes. With smart orientation, it can also accommodate a refrigerator or a motorcycle.

• Great fits: Queen/king mattress upright, bed frame, dresser, nightstands, small sofa/loveseat, desk or bookshelf, TV, and multiple boxes.
• Layout strategy: Stand the mattress along a wall, disassemble bed frames, use the dresser as a base for boxes, and limit stacks to four high for safety and access.
• Also possible: One refrigerator or a motorcycle alongside furniture when items are packed tightly and vertically.
• What’s tight: Large sectionals or multiple full bedroom sets—consider stepping up to a 5×15 or 10×10 in that case.
• Pro tip: Create a narrow front aisle so you can grab boxes and essentials without unloading the whole unit.

Step 9. What fits in a 5×15 storage unit (one bedroom)

A 5×15 gives you about 75 sq ft (≈600 cu ft with ~8 ft ceilings)—plenty for a full one‑bedroom setup. Think of it as a deeper 5×10: the extra length swallows a sofa, table, and bikes without needing a 10×10. Pack tall, stand mattresses upright, and leave a shallow front aisle so you can reach everyday boxes fast.

• Great fits: Queen/king mattress upright, bed frame, dresser, sofa/loveseat, desk, kitchen table with chairs, TV, and multiple boxes.
• Also possible: One large appliance (refrigerator) or a washer/dryer set, plus bikes or bookshelves when packed vertically.
• What’s tight: An oversized sectional or multiple full bedroom sets—consider a 10×10.
• Pro tip: Disassemble tables/bed frames and use dressers/bookshelves as sturdy bases; cap box stacks at four high.

Step 10. What fits in a 10×10 storage unit (one to two bedrooms)

A 10×10 gives you about 100 sq ft (≈800 cu ft with ~8 ft ceilings)—roughly half of a standard one‑car garage. It’s the go‑to for one to two bedrooms’ worth of furniture or an entire living room plus extras. With smart vertical stacking and a narrow center aisle, you can keep access without upsizing.

• Great fits: One to two bedroom sets (queen/king mattresses upright, bed frames, dressers, nightstands), sofa or small sectional, coffee/end tables, TV/stand, dining table with chairs, bookshelves, bikes, and plenty of boxes.
• Layout strategy: Stand mattresses against a wall; disassemble tables/frames; place heavy pieces (dressers, appliances) as box platforms; limit stacks to four high; leave a front‑to‑back center aisle for reach‑in access.
• Also possible: One large appliance (refrigerator) or a washer/dryer set alongside living room furniture and boxes.
• What’s tight: An oversized sectional plus multiple full bedroom sets or the contents of a three‑bedroom home—consider a 10×15 or larger.
• Pro tip: Build two stacking zones (left/right) and keep the aisle clear so you can swap boxes without a full unload.

Step 11. What fits in a 10×15 storage unit (two to three bedrooms)

A 10×15 gives you about 150 sq ft (≈1,200 cu ft with ~8 ft ceilings)—a generous jump from a 10×10. It’s sized for two to three bedrooms’ worth of furniture, plus living room pieces and several medium to large boxes. If your list includes a sofa, dining set, and multiple dressers with one or two appliances, this is the reliable “no‑sweat” choice in your self storage unit size guide.

• Great fits: Two to three bedroom sets (queen/king mattresses upright), dresser/nightstands, standard sofa or small sectional, dining table with chairs, bookshelves, bikes, and many boxes.
• Layout strategy: Line mattresses and tables (legs removed) along a wall, park heavy dressers/appliances as box platforms, and keep a narrow center aisle for reach‑in access.
• Also possible: One to two large appliances (fridge, washer/dryer), a desk, and an upright piano or large TV when stacked smartly.
• What’s tight: Full three‑bedroom house contents at once or oversized sectionals with multiple appliances; most vehicles need a 10×20+.
• Pro tip: Build left/right stacking zones and cap box stacks at four high to balance space and safety.

Step 12. What fits in a 10×20 storage unit (multi-bedroom home or a car)

A 10×20 delivers about 200 sq ft (≈1,600 cu ft with ~8 ft ceilings)—the classic “whole‑house” size. It comfortably handles the contents of a multi‑bedroom home, plus oversized pieces and large appliances. It’s also the standard for vehicle storage, making this the most versatile pick in any self storage unit size guide.

• Great fits: Multiple bedroom sets, large sectional or sofa, dining table with chairs, patio furniture, lawn equipment, refrigerators/washer–dryer, and a large quantity of boxes.
• Vehicle storage: A 10×20 typically fits most cars, trucks, and SUVs; compact cars may fit a 10×15, while longer vehicles often need a 10×25 or 10×30.
• Layout strategy: Build wall‑to‑wall stacks with a center aisle; stand mattresses, remove table legs, and use dressers/appliances as sturdy box platforms.
• What’s tight: Full home plus a vehicle together; oversized vans/trucks—size up to 10×25 or 10×30.
• Pro tip: Measure vehicle length bumper‑to‑bumper and verify door‑swing clearance before you book.

Step 13. What fits in 10×25 and 10×30 units (three to five bedrooms and oversized items)

Stepping up to the large end of the spectrum, a 10×25 delivers about 250 sq ft (≈2,000 cu ft) for the contents of a three–four bedroom home, while a 10×30 offers 300 sq ft (≈2,400 cu ft) to handle four–five bedrooms and extra‑long items. In this self storage unit size guide tier, think “whole home plus wiggle room.”

• Great fits: Multiple bedroom sets, large sectional, dining table with leaves, bookcases, patio furniture, lawn equipment, several large appliances, and a high volume of boxes.
• Long/oversized items: Kayaks/canoes, ladders, garage racks, long sofas, and bulky wardrobes fit more naturally in a 10×30.
• Vehicles (facility dependent): Some larger vans and trucks require a 10×25 or 10×30; longer vehicles often need at least a 10×30.
• Layout strategy: Build left/right wall stacks, stand mattresses upright, park appliances/dressers as box platforms, and keep a center aisle for reach‑in access.

Step 14. Size recommendations for special items (mattresses, sofas, appliances, pianos, motorcycles)

A few oversized or delicate pieces often decide your final unit size. Use the quick picks below to anchor your choice, then build the rest of your list around them. When in doubt, store tall and upright where safe—most units are about 8 feet high—so you minimize floor space and keep an aisle for access.

• Mattresses: Twin/full: 5×5. Queen: 5×10 recommended. King: 5×10+. Store upright along a wall.
• Sofas: Couch/loveseat: 5×10. Larger sectionals: 10×10–10×15. Stand on end if safe and stable.
• Appliances: Refrigerator: 5×10. Washer/dryer sets or multiple appliances: 10×10–10×15.
• Pianos: Upright or grand: 10×10 or larger; choose climate control for instruments.
• Motorcycles: Most bikes fit a 5×10 indoor unit; align diagonally and chock the wheel.

Step 15. Still deciding between two sizes? Compare these common scenarios

When you’re on the fence, anchor your choice to the biggest item and how tightly you’ll pack. If you want a clear center aisle for access, size up. Use these quick comparisons to finalize your pick in this self storage unit size guide.

• 5×5 vs 5×10: A queen/king mattress or small sofa pushes you to 5×10; mostly boxes, totes, and a twin/full mattress fit a 5×5.
• 5×10 vs 5×15: Full one‑bedroom with sofa and table = 5×15; a tightly packed studio can stay 5×10.
• 10×10 vs 10×15: Two bedrooms plus an appliance or sectional = 10×15; lighter two bedrooms = 10×10.
• 10×15 vs 10×20: Add a third bedroom, multiple appliances, or patio set? Go 10×20.
• 10×20 vs 10×25/30: Longer furniture, higher box count, or vehicle length needs? Step to 10×25/30.

Step 16. Layout tips to maximize space and access

Smart layout turns square feet into usable space. Choose a simple pattern, then build up, not out. Use the unit’s ~8 ft height, keep a walkable aisle, and stage frequently needed items near the door. These tips help you get more from the size you picked in this self storage unit size guide.

• Pick a layout: Center aisle for deep units; L or U for small.
• Stand tall items along walls: Mattresses, bookcases, sofas.
• Build platforms: Heavy furniture/appliances bottom; boxes on top; four‑high cap.
• Standardize box sizes: Align corners; avoid overhangs.
• Label toward the aisle: Keep a front grab zone.

Step 17. When to size up—and when a smaller unit will do

Choosing between two sizes comes down to access, item shape, and stackability. Use your inventory, 8‑ft height, and four‑box‑high stack plan to decide. If you’ll be in and out or you’re packing fragile, heavy, or awkward items, a little extra space saves time and wear.

• Size up when: You want a center aisle or frequent access; you have long/oversized pieces (sectional, kayak, king mattress); you’re storing multiple large appliances; your box count may grow; or you can’t safely stack four high.
• A smaller unit will do when: You’ll pack tightly with uniform boxes, disassemble furniture, stand mattresses upright, use dressers as platforms, won’t need a center aisle, and aren’t storing large appliances or instruments. This self storage unit size guide favors vertical wins over floor sprawl.

Step 18. How to reserve and move in at Keyless Storage in Sioux City

Reserving at Keyless Storage in Sioux City is quick and fully digital. Pick your size online, then enter with secure smartphone access 24/7. Every unit is ground‑floor, climate‑controlled, and protected by continuous video monitoring for a smooth, secure move‑in.

1. Choose a unit size and check availability.
2. Click Reserve/Rent, create an account, and complete checkout.
3. If unavailable, join the waiting list.
4. Get keyless mobile access instantly and move in anytime—no padlock needed.

Step 19. Quick answers to common storage size questions

Still have sizing questions? These quick answers cover the most asked so you can choose confidently without overpaying. Remember: dimensions refer to length x width; most units are about 8 feet tall, and exact interior space can vary slightly by facility.

• How tall are units? Most are ~8 ft; some are taller.
• Will a queen fit a 5×5? Very tight—go 5×10.
• Best size for a 1-bedroom? Usually 5×15; minimal: 5×10.
• Size for a car? Typically 10×20; compact 10×15; long 10×30.
• Size for a motorcycle? 5×10 suits most bikes.

Wrap-up and next steps

You’ve nailed the hard part—turning real items into a right‑sized plan. With your inventory, measurements, packing strategy, and the size benchmarks in this guide, you can choose with confidence, avoid overpaying for empty space, and still keep a simple aisle for access. If you’re between two sizes, remember: frequent access, oversized pieces, or limited stackability are smart reasons to size up.

Ready to book? Get climate‑controlled, ground‑floor units with 24/7 smartphone entry and continuous video security—no padlock required. Reserve your unit in minutes and move in on your schedule at Keyless Storage. If your ideal size isn’t open, join the waitlist and get notified fast.