Guide to Storage Unit Sizes for Homeowners
Short on space? Here’s where to start.
Deciding on a storage unit size can be daunting. You want to avoid renting a unit that’s too small and too crampy and one that’s unnecessarily expensive.
Let’s look at the problem:
Renting storage is already stressful, so most homeowners mess up their first storage unit size choice.
They end up in a small unit and need to move to a bigger one, paying additional fees. Or they rent large space they don’t actually need, wasting their money.
Wouldn’t it be great if you knew your ideal storage size before you even started looking? The best part is with the right storage unit size guide, you can!
The first step to finding the perfect storage unit is understanding the different storage unit sizes available and what they can hold.
From tiny 5×5 spaces to expansive 10×30 units, there is a storage size for every homeowner’s needs – whether that be seasonal storage or full house contents.
What you’ll learn:
- Storage Unit Size 101: The Basics for Homeowners
- Small Storage Units: The Perfect Size to Start With
- Medium Storage Units: Ideal for Most Storage Needs
- Large Storage Units: When You Need Extra Storage Space
- How to Choose the Right Size Unit (and Avoid Overspending)
Storage Unit Size 101: The Basics for Homeowners
Storage units are available in standard sizes listed in feet. The most common dimensions range from tiny 5×5 spaces to massive 10×30 units.
Here’s what most people don’t know:
Size isn’t the only factor. Height is also essential. The majority of storage units have 8-foot ceilings, but many facilities offer 10-foot and even 12-foot high units.
Square footage is the most talked about measurement:
The 5×5 has 25 square feet of floor space. A 10×10 has 100 square feet. It’s basic math, but it makes a big difference in how much stuff you can store.
In 2024, medium-sized units accounted for 40% of all storage market share in the U.S. They are the most popular sizes among renters, making them the go-to for most users. This data indicates the majority of people require more space than initially anticipated, but not as much as the biggest units.
Let’s put storage unit sizes into perspective:
- Small units (5×5 to 5×10): Closet to large walk-in closet
- Medium units (10×10 to 10×15): Bedroom to large bedroom
- Large units (10×20 to 10×30): One-car garage to oversized garage
Small Storage Units: The Perfect Size to Start With
Small storage units are the first size that most beginners choose. And, it works fine for particular purposes.
5×5 Storage Units
5×5 is the smallest standard-size unit most storage facilities offer. With 25 square feet of floor space, it’s the equivalent of a small walk-in closet.
Fits in a 5×5 storage unit:
- 15-20 boxes
- Seasonal decorations
- Small furniture pieces, like end tables and small chairs
- Clothes and personal belongings
- Small appliances (coffee maker, mini fridge)
The problem is a 5×5 storage unit doesn’t fit much furniture. You can barely fit in a chair and small dresser, but not couches, mattresses, or larger appliances.
5×10 Storage Units
With 50 square feet, the 5×10 is double the size of a 5×5 unit and feels more spacious. It’s a perfect starter size for people needing a bit more room.
Ideal for storing in a 5×10 unit:
- Queen size mattress and box spring
- Small couch or loveseat
- Up to 30 boxes
- Motorcycle (yes, really!)
- Seasonal items like holiday decorations
The 5×10 storage unit is ideal because it’s still relatively affordable but also large enough for actual furniture pieces.
Medium Storage Units: Ideal for Most Storage Needs
Medium storage units are where most homeowners end up. The reason is these sizes offer the best of both worlds.
10×10 Storage Units
The 10×10 storage unit is the most popular size, and with good reason. A 100 square foot unit is like having an extra bedroom just for your stuff.
Perfect for storing in a 10×10 unit:
- Contents of a studio apartment or one-bedroom apartment
- Multiple mattress sets
- Small living room furniture set (couch, chairs, coffee table)
- Major appliances like washers and dryers
- 50-60 boxes, plus furniture
The thing that makes a 10×10 work so well is you can walk around inside it. That makes accessing your items way easier than if you had to cram everything into a smaller space.
10×15 Storage Units
Bump up to 150 square feet, and you’ve got a ton of space for a small house’s worth of stuff. The 10×15 is great for bigger families or people who own a lot of furniture.
Perfect for storing in a 10×15 unit:
- Contents of a three-bedroom house
- Large appliances, like refrigerators, entertainment centers
- Dining room sets
- Office furniture
- Seasonal items plus your regular furniture
The extra 5 feet of depth makes a big difference. You can create walkways and still fit bulky items.
Large Storage Units: When You Need Extra Storage Space
Large storage units are for people who need to store the contents of an entire house or those with specific needs like vehicle storage.
10×20 Storage Units
200 square feet of storage space is the equivalent of a one-car garage. 10×20 units are great for three to four-bedroom houses.
Use a 10×20 for:
- Contents of an entire household
- Large furniture collections
- Multiple appliances
- Seasonal items, plus regular storage
- Small vehicles (many facilities allow this)
10×30 Storage Units
The 10×30 is typically the largest unit that most storage facilities offer. With 300 square feet, it’s massive, like a large one-car garage.
Why you need a 10×30:
- Four+ bedroom house
- Commercial inventory
- Vehicle storage
- Long-term storage for multiple households
- Estate situations
Warning: 10×30 and other large units cost a lot of money fast. Make sure you need all that space before you rent it.
How to Choose the Right Size (and Avoid Overspending)
Renting the wrong size costs you money. Too small, and you’ll have to upgrade and pay moving fees. Too big, and you’re paying each month for empty space.
Here’s my three-step process:
Step 1: Make a list of everything you’re storing. Be as specific as possible.
Step 2: Measure the largest pieces (couches, mattresses, appliances).
Step 3: Use this general rule:
- Studio apartment or one-bedroom apartment = 5×10 or 10×10
- Two-bedroom house = 10×10 or 10×15
- Three-bedroom house = 10×15 or 10×20
- Four+ bedroom house = 10×20 or 10×30
Step 4: When in doubt, size down one level than you think you need. You can always upgrade, but it’s harder to downsize.
Pro tip: Visit the facility and see the actual units. Photos online are deceiving. The in-person visit makes a world of difference.
33% of Americans currently using self storage shows you’re not alone. People are storing more stuff than ever before.
The trick is to know your ideal storage size before you even look at units. That way, you can find the right size from the start.
Don’t forget about other factors that affect price:
- Climate control (costs more but protects valuables)
- Access hours (24/7 vs. limited)
- Security features (cameras, gates, lighting)
- Location (farther cheaper but more time)
Most storage companies allow you to switch sizes if needed, but that’s annoying. Get it right the first time, and you avoid problems later.
Wrapping Things Up
Choosing the right storage unit size doesn’t have to be hard. Begin with your actual storage needs. Don’t rent based on what you think you may need some day.
Small units are perfect for seasonal storage and decluttering projects. Medium storage units accommodate the contents of most houses with room to spare. Large storage units are for more significant circumstances like moving or storing multiple households.
10×10 remains the most popular size because it hits the sweet spot of being big enough to store real furniture but not too expensive.
Remember the main takeaways:
- Measure the largest items first
- Think about how you’ll arrange the items
- Plan for future storage needs
- Factor in the total cost (rent, insurance, supplies)
Visit facilities and view the units in person. What looks massive on a website can feel cramped when you’re trying to shove a couch through the door.
Choosing the right storage unit size ensures you get the exact space you need and pay only for what you use. Get it right, and you’ve found the perfect, convenient, and affordable home for all your extra stuff.
