Rent a unit that's too small and you'll be tetris-ing boxes at midnight. Rent one that's way too big and you're paying for air. The good news is picking the right size isn't complicated once you know what to actually look at.
This guide walks through the five-step process we use to help folks in Southbury, Newtown, Woodbury, Middlebury, Oxford, and Roxbury pick the right storage unit. It includes a real breakdown of every common size, what actually fits in each, and a checklist you can run through before you rent.
The 5-Step Storage Unit Sizing Process
Take an inventory of what you're storing
Walk through your space and list out the large items (furniture, appliances, vehicles) plus roughly how many boxes you'll have. You don't need an exact count, a rough estimate is fine. Most people underestimate, so round up.
Identify your bulkiest items
The size of your unit is usually driven by one or two big items, not by the total box count. A couch, mattress, fridge, or dining table sets the floor space you need. Measure these if you can.
Decide how often you'll need access
Storing stuff long-term and forgetting about it? You can pack tight and go smaller. Needing to pull things in and out regularly? Size up one step so you can leave a walkway to the back of the unit.
Account for vertical space
Most of our units are 7โ8 feet tall. That's real stackable space. A 10x10 isn't just 100 square feet, it's 700โ800 cubic feet when you use the height. Good shelving or sturdy stacking doubles your usable capacity.
When in doubt, size up
Jumping from a 5x10 to a 10x10 often costs less than you'd expect, and the extra breathing room makes both move-in day and future retrieval way less stressful. We'd rather see you comfortable than crammed.
Complete Storage Unit Size Guide
Here's what actually fits in each size. These are real-world estimates from watching hundreds of people move in and out of our units in Southbury.
Storage Locker
The smallest unit we offer. Perfect for stashing a handful of boxes, seasonal decor, off-season clothing, or documents you want out of your house but not in a commercial file storage place.
Typically fits
- 15โ25 standard boxes
- Holiday decorations
- Seasonal clothing bins
- Small camping or sports gear
- Important documents
Best for
- Apartment dwellers with overflow
- College students on break
- Seasonal item rotation
- Business document storage
Closet-Sized Unit
Think of a standard walk-in closet. This size comfortably holds the contents of a single room you're clearing out, or the overflow from a small apartment.
Typically fits
- A dorm room's worth of stuff
- Small furniture (chair, end table, dresser)
- 30โ50 boxes
- A couple of bikes
- Seasonal yard equipment
Best for
- College students
- Home office decluttering
- Single-room cleanouts
- Small business inventory
Studio Apartment Size
Long and narrow, like a small bedroom. This is one of our most popular sizes because it handles the contents of a studio or one-bedroom apartment with room for some walking access.
Typically fits
- Contents of a studio apartment
- Queen mattress and box spring
- Sofa or loveseat
- Dresser, small dining set
- 60โ75 boxes
- Motorcycle (depending on dimensions)
Best for
- One-person moves
- Downsizing from apartment to condo
- Deployment or temporary relocation
- Estate cleanouts (partial)
One-Bedroom Apartment
The workhorse size. A 10x10 is roughly a small bedroom and comfortably holds the furniture from a full one-bedroom or small two-bedroom apartment with some boxes mixed in.
Typically fits
- Contents of a 1-bedroom apartment
- King mattress set
- Full living room (sofa, chairs, coffee table)
- Large appliances (fridge, washer, dryer)
- 100+ boxes
- Small business inventory
Best for
- Apartment moves
- Home renovations
- Staging while selling a house
- Contractor tool & material storage
Two-Bedroom Home
A step up for bigger moves. A 10x15 handles the furniture and household goods from a two- or three-bedroom home with breathing room left over.
Typically fits
- Contents of a 2-3 bedroom home
- Multiple bedroom sets
- Full dining room set
- Living room + family room furniture
- 150+ boxes
- Lawn equipment and bikes
Best for
- Whole-home moves
- Major renovations
- Combining households
- Larger estate situations
Three-Bedroom+ Home
Our largest standard size. About the size of a one-car garage. If you're storing a whole house or a vehicle plus household goods, this is usually the right call.
Typically fits
- Contents of a 3-4 bedroom home
- A car, truck, or small RV
- Vehicle + boxes and furniture
- Large business inventory
- Contractor equipment
- 200+ boxes
Best for
- Full home relocations
- Vehicle + household combo storage
- Small business overflow
- Long-distance moves
Exact availability changes daily. Our Rent Now page updates in real time, so you can see what's actually available right now and the exact dimensions of each unit.
Quick Size Comparison
A cheat sheet for comparing sizes at a glance:
| Size | Square Feet | Visual | What Fits | Typical Use |
|---|---|---|---|---|
| 4x3 Locker | 12 sq ft | Small closet | 15โ25 boxes, seasonal items | Overflow, documents |
| 5x5 | 25 sq ft | Walk-in closet | Dorm room, small furniture | Students, decluttering |
| 5x10 | 50 sq ft | Small bedroom | Studio apartment | Single-person moves |
| 10x10 | 100 sq ft | Small bedroom | 1-bedroom apartment | Apartment moves, renos |
| 10x15 | 150 sq ft | Large bedroom | 2-3 bedroom home | Whole-home moves |
| 10x20 | 200 sq ft | One-car garage | 3-4 bedroom home or vehicle | Large moves, vehicles |
Common Storage Sizing Mistakes
1. Sizing based on floor space, not volume
A 5x10 isn't just 50 square feet, it's 350+ cubic feet when you factor in the 7 foot ceiling. People who forget to stack end up paying for a bigger unit than they need. A $20 shelving unit from the hardware store can easily double your usable space.
2. Forgetting the walkway
If you're storing long-term and never touching anything again, pack it floor to ceiling. But if you'll need to grab the Christmas decorations in December or your golf clubs in April, leave a narrow walkway down the middle. Otherwise you'll be unloading half the unit to reach that one box in the back.
3. Renting for today, not the next 6 months
Think about what you might add. Home renovation turning into a bigger project? Planning to clear out the basement next? It's usually cheaper to go one size bigger now than to move your stuff again in three months.
4. Ignoring the shape of the unit
A 5x10 and a 10x5 have the same square footage but feel completely different. Long narrow units are better for smaller items and boxes; more square units handle large furniture better. Check the dimensions before renting, not just the square footage.
Pro Packing Tips to Save Space (and Money)
Use same-sized boxes
Uniform box sizes stack way more efficiently than random shapes. Grab a stack of medium moving boxes from any hardware store and you'll fit more in less floor space.
Stand mattresses and sofas on their edges
A mattress stood on its long edge against a wall takes up a fraction of the floor space it would laying flat. Same goes for most couches.
Fill furniture with soft items
Dresser drawers, cabinets, nightstands โ fill them with clothes, linens, or pillows. You're paying for the space anyway, might as well use every cubic inch.
Disassemble what you can
Bed frames, dining tables, bookshelves, anything that comes apart should come apart. A disassembled bed frame takes up maybe 5% of the space of an assembled one. Tape hardware to the pieces in a labeled bag.
Stack vertically with care
Heaviest boxes on the bottom, lightest on top. Never stack boxes directly on upholstered furniture (compresses the cushions). Shelving makes stacking safer and easier to access.
Leave a walkway (seriously)
Unless you're absolutely certain you'll never dig through your unit, leave a 2-foot-wide aisle down the middle. Future you will thank present you.
Does Unit Size Affect the Climate Control Decision?
Sort of. The question is really what you're storing, not how much, but size plays a role.
Smaller units (lockers, 5x5, 5x10)
These often hold personal items, documents, photos, or smaller electronics. Climate control is usually worth it at this size because you're storing things with high sentimental or replacement value.
Medium units (10x10, 10x15)
Holding full apartment or home contents. Climate control matters if you have wood furniture, electronics, leather, artwork, or musical instruments. Heated-only is fine for bulk household goods that can handle temperature swings.
Large units (10x20+)
Whole-home storage or vehicles. Whether you need climate control depends heavily on what's inside. Vehicles and hardy items don't need it. Mixed contents with sensitive items probably do.
Our quick rule
If you'd be upset to see it damaged by heat or humidity, get climate control. If it lives in an uninsulated garage or shed at home, you probably don't need it. More on this in our climate control FAQ.
Sizing for Vehicle Storage
If you're storing a car, truck, motorcycle, trailer, or small RV, size depends on vehicle dimensions, not a set standard.
Motorcycles
Most motorcycles fit comfortably in a 5x10 unit, sometimes smaller depending on the bike.
Compact and mid-size cars
Usually fit in a 10x15, though a 10x20 gives you room to open doors comfortably and store a few items around the vehicle.
Trucks, SUVs, and larger vehicles
Full-size trucks and SUVs typically need a 10x20. Measure your vehicle's length and width, and add a couple of feet for clearance.
Trailers and boats
Depends entirely on length. Bring us the dimensions and we'll help figure out the right fit.
All of our vehicle storage at Southbury Self Storage is indoor, which means your vehicle stays out of the rain, snow, and summer sun. A big upgrade over leaving it outside through Connecticut winters.
Your Pre-Rental Checklist
Run through this before renting and you'll nail the size on the first try:
Before You Rent
- Take an inventory of large furniture and appliances
- Estimate your total box count (round up!)
- Identify your biggest single item and measure it
- Decide how often you'll need access
- Plan whether you'll use shelving to stack vertically
- Consider climate control for sensitive items
- Check vehicle dimensions if storing a car/truck
- Size up one step if you're on the fence
- View real-time availability on our Rent Now page
Still not sure what size you need?
Call or text us. We've helped hundreds of folks figure this out, and we'll shoot you straight on what fits.
๐ Call or Text 203-264-8272 View Available UnitsStorage Unit Size FAQs
What's the most common storage unit size?
The 10x10 is the most popular size nationally and locally. It holds the contents of a typical one-bedroom apartment or a small two-bedroom home and hits the sweet spot on price-to-space.
Is it better to size up or down?
Size up. The difference in monthly cost between sizes is usually small, and the stress of trying to cram everything into a too-small unit (or needing to rent a second one) is significant.
How long does it take to pack a storage unit?
Faster than you'd think with the right approach. A 5x10 can usually be packed in an hour or two if your stuff is already boxed and you have a dolly. A 10x10 takes 2โ4 hours. Using our free carts and hand trucks makes a big difference.
Can I switch unit sizes if I picked wrong?
Yes. Every rental is month-to-month with no long-term contracts, so you can move to a different unit size whenever one becomes available. Just give us a call.
Do you have the size I need right now?
Availability changes daily. Check our real-time availability page, and if the size you want isn't listed, join the waiting list. Turnover is frequent.