Do you know if your storage units are the right size for your tenants?
Few property managers do. They develop an entire row of units and overprice each one hoping they will all sell. Then wonder why half of them don’t sell for months.
Here’s the truth…
Unit size is one of the largest determinants whether your space will be rented or ignored completely. Size it correctly and you will rent units quickly. Size it wrong and you lose revenue every month.
The good news?
When you understand the mechanics of storage unit size, you can effectively plan your unit mix. You don’t need a degree in physics for that.
Let’s break it down…
What’s Inside This Guide:
- Why Storage Unit Size Matters in Real Estate
- The Most In-Demand Storage Unit Sizes
- How To Match Unit Sizes To Your Tenants
- Sizing Mistakes That Cost You Money
Why Storage Unit Size Matters in Real Estate
Storage unit size affects more than just how it looks on a floorplan. It directly impacts your rental revenues, occupancy levels and tenant satisfaction.
Think about it like this…
Someone looking to store an entire one-bedroom apartment isn’t going to rent a closet sized locker. And a person storing a couple boxes doesn’t need 300 square feet storage units, which are perfect for an entire home. It just needs to suit what you are storing.
Units that are properly sized for demand will rent FAST. Those that aren’t will gather dust (AND lose you money each day).
And here’s the part most people miss…
Self-storage is HOT right now. Self-storage locations are wanted all over the country. From the SSA 2025 Demand Study, self-storage usage by households increased to 12.6% in 20 24. That equals about 1 out of every 8 homes nationwide. With increased demand comes the opportunity to rent your units — if you have sizes people are looking for.
So the question becomes: which sizes should you offer?
The Most In-Demand Storage Unit Sizes
Different storage unit sizes don’t rent alike. Some sizes are all workhorse. Others don’t rent at all.
Here’s a quick breakdown of the sizes every property manager should know:
- 5×5 (small): Fits about the size of a small closet. Perfect for boxes, seasonal decorations, a few miscellaneous small items.
- 5×10 (small-medium): Holds the contents of a small bedroom or a studio apartment.
- 10×10 (medium): By far the most popular size. Enough room for either a one or two-bedroom apartment comfortably.
- 10×20 (large): Stores a full house or even a car. Ideal for families on the go.
- 10×30 (extra-large): Think Big. Order Extra-Large. Whole homes, vehicles, piles of business inventory.
So which size should you lean on the most?
The popularity of self-storage can be mostly attributed to the size of a unit known as the 10×10. According to market research, units of this size generated roughly 35.6% of revenue in 2025. Simply put, everyone eventually needs around ten-by-ten feet of storage space in their lives.
Just don’t fall into the beginner’s trap of stocking your entire inventory with only one size. Variety is good. It covers all your tenants.
(More on that in just a second.)
How To Match Unit Sizes To Your Tenants
Here’s where most property managers go wrong…
They speculate. Or they mimic whatever their competitor across town is doing. But the optimal product mix is always derived by knowing who your tenants really are.
Start by asking yourself a few simple questions:
- Are your tenants apartment dwellers or homeowners?
- Do renters in your area move around often?
- Are there small businesses nearby that need extra space?
The answers tell you almost everything you need to know.
When dealing with apartments and condos nearby, focus on small and medium. Tenants will need space to store furniture when moving in and out. They will also store seasonal items during the other months.
If you have family homes nearby mix in additional larger units. Families need space for furniture, appliances and all the accumulated belongings they acquire. They will happily fill those larger units.
Oh and by the way, don’t forget businesses either. Businesses love bigger units to store inventory and equipment. The best part, they usually rent for extended periods of time providing you with great cash flow.
Match the size to the need and your units practically rent themselves.
It really is that simple.
Sizing Mistakes That Cost You Money
Property managers make this mistake too. Let’s review the most typical storage unit sizing mistakes you’ll want to avoid:
Too many big units. Big units look nice on your lot but they fill slower. If there isn’t enough demand in your area you will be left with blocks of concrete.
Too many small stalls. Small lockers may be economical to construct, however they yield lower rental income per square foot. Overbuild small and it hurts your bottom line.
Discounting the statistics. Conditions change all of the time. Believe it or not, occupancy across the country went down, settling at about 82% sometime in late 20 25 according to industry tracking. This makes selecting the proper size more important than ever.
One-size-fits-all thinking. There isn’t ONE size that fits all of the people that enter your door. Diversity is always the safer play.
Steer clear of these 4 pitfalls and you’ll maintain high occupancy and happy REAL tenants.
Tying It All Together
Storage unit size is one of the most important — and most overlooked — aspects of storage real estate management. Choose correctly and you’ll fill units faster, collect more rent, and keep tenants returning time and time again.
To quickly recap:
- Storage unit size directly affects your income and your occupancy
- 10×10 is most common however you’ll still want variety
- Match your unit sizes to the real tenants in your area
- Don’t overbuild any single size
- Keep an eye on market data and adjust as things change
Winning property managers don’t view sizing of units as an afterthought – they make it strategy.
Begin strategizing about your unit mix now and see your storage square footage start paying dividends.