What Size Storage Unit Do I Need? Complete Guide

Picking the wrong storage unit size is one of the most common mistakes renters make. Too small and you are stuck playing Tetris with your couch. Too big and you are throwing money away on empty floor space every single month.

This guide covers every standard storage unit size with real-world comparisons, business use cases, vehicle storage options, and a step-by-step method for calculating exactly what you need. Whether you are moving across town, renovating your home, or running a business out of Indianapolis or Tulsa, you will find the right fit here.

Storage Unit Sizes at a Glance

*Prices vary by location and whether the unit is climate-controlled.

5x5 Storage Unit (25 Square Feet)

Room equivalent: A standard walk-in closet. Stand in yours at home. That is roughly the space you are working with.

Car analogy: About the same volume as the trunk and back seat of a midsize sedan, stacked floor to ceiling.

What fits:

• 10 to 15 medium moving boxes
• A small dresser or compact desk
• Seasonal clothing bins and holiday decorations
• Sporting equipment like golf clubs, skis, or camping gear
• Filing cabinets and small business records

Best for personal use:

• College students storing belongings over summer break
• Apartment dwellers who need extra closet space
• Seasonal decoration and clothing rotation
• Keeping a few boxes of personal files safe

Best for business:

• Document storage and record keeping
• Small e-commerce sellers with limited inventory
• Photographers storing backup equipment

Real scenario: Sarah, a college student in Milwaukee, rents a 5x5 each May. She stores her mini fridge, desk lamp, winter clothes, and about a dozen boxes. It costs her less than one month of dorm fees and saves her from hauling everything home to Michigan.

5x10 Storage Unit (50 Square Feet)

Room equivalent: A small bedroom or large walk-in closet. Think of a room about 5 feet wide and 10 feet deep. Not huge, but surprisingly capable when you stack smart.

Car analogy: Picture the entire interior of a minivan, floor to roof.

What fits:

• Contents of a studio apartment or dorm room
• A mattress set, small sofa, and 15 to 20 boxes
• A motorcycle or pair of ATVs
• Full-size dresser, desk, bookshelf, plus boxes
• Small business inventory and display materials

Best for personal use:

• Moving out of a studio or one-room apartment
• Storing furniture from a single room during renovations
• Motorcycle and recreational equipment storage
• Between apartments and need a place for your stuff

Best for business:

• Craft show vendors storing display tables and inventory
• Real estate agents storing staging furniture
• Cleaning companies storing supplies and backup equipment

Real scenario: Marcus runs a small landscaping business out of Olathe. During the winter months, he stores his commercial mower, leaf blower, and hand tools in a 5x10. Come spring, he pulls it all out and gets back to work without cluttering his home garage.

If you are renting your first unit, check out our tips for first-time renters before you move in.

10x10 Storage Unit (100 Square Feet)

Room equivalent: A standard bedroom, roughly 10 feet by 10 feet. This is the most popular storage unit size in America for good reason.

Car analogy: About the interior volume of a full-size SUV, stacked to the ceiling.

What fits:

• Full contents of a 1-bedroom apartment (bed, couch, dining set, dresser, TV, 20+ boxes)
• Two complete rooms of furniture
• Seasonal items combined with major furniture pieces
• A home office setup plus excess household belongings
• Appliances like a washer, dryer, or refrigerator

Best for personal use:

• Moving out of a 1-bedroom apartment
• Home renovation where you need to clear one or two rooms
• Growing families who need overflow space
• Downsizing and deciding what to keep

Best for business:

• Home-based businesses with moderate inventory
• IT companies storing retired equipment
• Event planners keeping supplies and decor between gigs

Real scenario: The Nguyen family in Columbus renovated their kitchen and living room at the same time. They moved both rooms of furniture into a 10x10, stacked boxes along the back wall, and still had room to walk in and grab things they needed during the three-month project.

10x15 Storage Unit (150 Square Feet)

Room equivalent: A large master bedroom. You have real room to work with at this size.

Car analogy: Similar to the cargo area of a small box truck or cargo van.

What fits:

• Full contents of a 2-bedroom apartment
• Three rooms of furniture plus 25 to 30 boxes
• Large appliances including washer, dryer, and refrigerator
• A compact car, large motorcycle, or jet ski

Best for personal use:

• Moving out of a 2-bedroom apartment or small house
• Families between homes who need everything stored
• Storing contents of multiple rooms during a major renovation
• Combining two households into one

Best for business:

• Retail stores with seasonal inventory overflow
• Contractors storing tools, materials, and fixtures
• Catering companies keeping tables, chairs, and equipment

Real scenario: Jake and Lisa combined households when they got married. They kept Jake's apartment furniture in a 10x15 at the Best Self Storage Facility in Meriden while they figured out what to keep and what to sell. Three months later they downsized to a 5x10, then closed the unit entirely.

Find 10x15 units at our Meriden, CT and New Britain, CT locations.

10x20 Storage Unit (200 Square Feet)

Room equivalent: A standard one-car garage. If you can picture your garage at home, you have the right mental image.

Car analogy: Roughly the cargo space of a 15-foot moving truck. You can literally park a full-size car or truck inside.

What fits:

• Full contents of a 3-bedroom house
• Complete household furniture, all appliances, and 30+ boxes
• A car, truck, or SUV (with room to spare for boxes along the sides)
• Large business equipment, shelving units, and bulk inventory

Best for personal use:

• Whole-house moves and long-distance relocations
• Long-term household storage between homes
• Vehicle storage combined with household items
• Estate storage when settling a family member's belongings

Best for business:

• Contractors storing heavy equipment, lumber, and tools
• E-commerce businesses with warehouse-level inventory
• Restaurants storing backup equipment and seasonal furniture
• Auto detailers or mobile mechanics storing supplies

Real scenario: Tom relocated from Sterling Heights to Texas for a one-year work assignment. He stored his entire 3-bedroom house in a 10x20, including his riding mower. When he came back, everything was exactly where he left it. Voted #1 Facility in Sterling Heights, we made the process painless.

10x30 Storage Unit (300 Square Feet)

Room equivalent: One and a half car garages side by side. This is a serious amount of space.

Car analogy: Comparable to a 20-foot moving truck. You could park two vehicles in here if you needed to.

What fits:

• Full contents of a 4 to 5 bedroom house, including garage items
• Multiple vehicles or a boat
• Large-scale business inventory and commercial equipment
• An entire household plus outdoor furniture, tools, and sporting equipment

Best for personal use:

• Large family moves with significant belongings
• Military families on extended deployment or overseas assignment
• Storing everything during extended travel or sabbatical
• Estate storage when managing a deceased family member's property

Best for business:

• Warehousing on a budget for growing companies
• Construction firms storing machinery and materials between jobs
• Dealerships or resellers with vehicle inventory
• Nonprofit organizations storing donation inventory

Real scenario: The Rodriguez family in Joliet used a 10x30 when their father passed away. They needed time to sort through a lifetime of belongings from a 4-bedroom house plus a packed garage. Having everything in one unit instead of scattered across multiple smaller ones made the process much easier during a difficult time.

Vehicle Storage Sizing

Storing a vehicle? Here is what you need.

A few things to keep in mind with vehicle storage. Disconnect the battery or use a trickle charger. Keep the gas tank at least half full to prevent moisture in the tank. Place a vapor barrier or tarp under the vehicle. And if you are storing long-term, consider a climate-controlled unit to protect against temperature swings.

Our Antelope, CA location is a popular choice for vehicle storage in the Sacramento area. Best Self Storage Facility in Antelope, with wide drive aisles and easy access.

How to Calculate What Size You Need

Follow these four steps and you will get it right the first time.

Step 1: Take a Room-by-Room Inventory

Walk through your home with a notepad or your phone. Write down every major item you plan to store.

Living room: Sofa, loveseat, coffee table, end tables, TV stand, entertainment center, lamps, rugs, wall art

Bedroom: Bed frame, mattress, box spring, dresser, nightstands, mirror, desk, chair

Kitchen: Table, chairs, small appliances (if moving out entirely, add the refrigerator, stove, dishwasher)

Bathroom: Cabinets, hampers, shelving

Garage/Basement: Tools, workbench, bicycles, lawn equipment, holiday decorations, sporting goods

Boxes: Count them honestly, then add 30%. Almost everyone underestimates the number of boxes they will need.

Step 2: Apply the Room Rule of Thumb

This simple formula works for most people:

• 1 room of furniture = 5x10
• 2 rooms = 10x10
• 3 rooms = 10x15
• 4 or more rooms = 10x20 or larger
• Entire large house = 10x30

Step 3: Factor In Odd Items

Do you have a piano, treadmill, kayak, or commercial equipment? These bulky items eat up space fast. Add one size increment for every two or three oversized items.

Step 4: Add a Buffer

If you land right between two sizes, go up. The cost difference is usually $20 to $40 per month. That small bump gets you breathing room for loading, a walkway for access, and space for items you forgot about. You will thank yourself later.

For detailed packing strategies that help you maximize your space, read our guide on how to pack a storage unit.

Real Customer Scenarios

The Downsizer: Carol in Parma Heights sold her 3-bedroom house and moved into a 1-bedroom condo. She rented a 10x15 to store the furniture and keepsakes that did not fit. Over six months, she gradually donated and sold items, eventually downsizing to a 5x10.

The Renovator: Mike and Jen in Redford gutted their main floor. They moved the living room, dining room, and kitchen contents into a 10x15 for four months. Having everything off-site meant the contractors could work faster and nothing got damaged by dust or debris.

The Military Family: Staff Sergeant Davis and his family received PCS orders from Saint Charles to Germany for three years. They packed their entire 4-bedroom house into a 10x30 with climate control. Voted #1 Facility in Saint Charles, our team helped coordinate the move-in around their tight timeline.

The Side Hustler: Amy runs an Etsy shop from her apartment in Urbandale. She started with inventory stacked in her living room, then rented a 5x5. Now she uses a 5x10 to store supplies, finished products, and shipping materials. It keeps her home livable and her business organized.

Business Storage Use Cases

More businesses use self storage than you might expect. Here is how different industries use each size.

5x5 and 5x10: Accountants and lawyers storing client files. E-commerce sellers with small, lightweight inventory. Photographers keeping backup gear and props. Real estate agents storing signs and lockboxes.

10x10 and 10x15: Retail stores managing seasonal overflow. Cleaning companies storing equipment and bulk supplies. Event planners keeping furniture, linens, and decor. IT companies retiring old hardware.

10x20 and 10x30: Contractors and construction crews storing tools, lumber, and machinery between jobs. Restaurants keeping backup equipment and seasonal patio furniture. Auto dealers storing overflow inventory. Nonprofits warehousing donations.

Our Richmond Heights and Saginaw locations see especially strong demand from local businesses. Best Self Storage Facility in Richmond Heights for commercial tenants.

Money-Saving Tips

1. Right-size from the start. A unit that sits half empty wastes money every month. Use the calculator above and be honest about what you are storing.
2. Stack vertically. Use sturdy shelving and stack boxes to the ceiling. You are paying for cubic feet, not just square feet.
3. Disassemble everything you can. Remove table legs, break down bed frames, take shelves off bookcases. Flat items take up dramatically less space.
4. Seasonal swap. If you only need storage for holiday decorations and winter gear, a 5x5 is probably enough.
5. Ask about move-in specials. Many JustSelfStorage locations offer first-month-free or discounted rates. That saves $50 to $150 right off the bat.
6. Stay month-to-month. Avoid long-term contracts so you can downsize or cancel the moment you are ready.
7. Reassess every few months. Your storage needs change. If you have been pulling items out, call the front desk and ask about transferring to a smaller unit.

Frequently Asked Questions

Find a JustSelfStorage Location Near You

We have 18 locations across the country, each with a range of unit sizes and flexible month-to-month leases. Find the one closest to you: