How to Estimate the Storage Unit Size You Need

Kurt Manwaring
Researcher & Writer
Read More
February 02, 2023
7 min read

At a glance

The price difference between small and medium storage units is more than $1000 per year—even if you use one of the best self-storage companies. That means it pays to estimate the storage unit size you need before renting a unit. Regardless of whether you need temporary storage during a remodel or your garage is bursting at the seams after moving, these five steps could save you hundreds of dollars:

  1. Perform an inventory of your belongings
  2. Double-check your home storage
  3. Calculate your space
  4. Pick a small, medium, or large storage unit size
  5. Research specific measurements

Bonus: Be sure to check out our list of pro tips on how to save money when selecting a storage unit.

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5 steps to estimate the storage unit size you need

1. Perform an inventory of your belongings

The first step to estimating the storage unit size you need is to see how much stuff you have. Count all of your boxes and identify larger items like couches, tables, and bookshelves. Be sure to write everything down so you can refer back to it later.

For example, if you want to store the contents of a small bedroom in a self-storage unit, your inventory might look like this:

Make a written list of everything you plan to put in your storage unit. You’ll need it to estimate what size you need.

As you perform your inventory, keep track of things that may require climate-controlled storage. Sensitive items like business documents, photographs, and art will require lower humidity and temperature—something you'll only get in climate-controlled storage units.

2. Double-check your home storage options

After you’ve inventoried every room, the next step is to make sure you’ve used all of your home’s available storage space. The last thing you want is to pull the trigger on a storage unit, only to realize you could have purchased a smaller (and cheaper) one by storing some of your things in a partly empty closet or an unused corner of your garage.

The difference between a small and medium-sized storage unit is about $1000 per year, so it’s worth taking five minutes to double-check your options.

Info Box
What fits in a small storage unit?

Small storage units are 5 feet long and 5 feet wide, so it will typically fit no more than 50 square feet of belongings. People often store smaller items like outdoor gear, patio furniture, small furniture, and seasonal items in small units.

3. Calculate your space

The third step to estimating the storage unit size you need is to measure your belongings. When you pick a storage unit size in Step 4, you’ll want to have one of two measurements:

  1. Square feet (sq. ft.). Multiply the length and width of your belongings. If they make a pile that’s 5 x 5 feet, you’d need a storage unit with at least 25 square feet (Extra Space Storage has excellent 5 x 5 storage units).
  2. Cubic feet (cu. ft.). Multiply the length, width, and height of your belongings. If your larger items make a pile that measures 5 x 5 x 5 feet, you’d need a storage unit with at least 75 cubic feet.

There’s no one right way to measure your stuff. One approach is to put all your things into a pile and measure the stack to determine your storage need. Another option is to individually measure each item’s length, width, and height. For a little extra help, take a look at Extra Space Storage's moving calculator.

Anything works so long as you have an estimate of your square or cubic footage for the self-storage unit. For help calculating measurements in feet, check out our guide to measuring linear and square feet

Heads Up
What do I use to measure my belongings?

You can use a standard tape measure, yardstick, or even a ruler to measure your stuff. Just jot down the measurement on your cell phone and compare it to available storage unit sizes.

4. Pick a small, medium, or large storage unit size

After you measure everything, determine whether you need a small, medium, or large unit. There are dozens of storage unit sizes, but they all boil down to these three categories. Small units hold up to 50 square feet of belongings, medium units cap out at 150 square feet, and large units can fit as much as 300 square feet. storage unit size guide

Common dimensions (feet)
Square footage
Cubic footage
What fits
Small5 x 5–5 x 1025–50200–400Up to 1 room
Medium5 x 15–10 x 15 75–150600–1,200Up to 3 rooms
Large10 x 20–10 x 30200–3001,600–2,400Up to 5 rooms

Sizes, dimensions, and details are estimates and may vary by location.

Some companies like CubeSmart also have extra-small units called storage lockers.  These are ideal if you live in a big city and have a storage need for things like boxes, holiday decorations, and winter clothing.

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CubeSmart's storage lockers are about the size of hall closets—but half as tall.

The easiest way to pick an initial size is to compare your measurements from Step 3 with the storage unit size guide above. For example, if your inventory measurements equal 125 square feet, you’d want a medium storage unit because its size range is 75–150 square feet.

How tall are storage units?

Most storage units are about eight feet tall—meaning 6’ 9” Lebron James would have just over one foot of space between his head and the ceiling.

5. Research specific measurements

The fifth step to estimating the storage unit size you need is to check with storage facilities and pick an exact size. You can save money by choosing a unit big enough to store your larger items—but not so huge that you have lots of leftover space.

In Step 4, you narrowed down your options to a small, medium, or large unit. Now, you want to look at storage unit websites to get more specific measurements and see what the companies say will fit (they all have slightly different recommendations).

We recommend checking with our top storage unit companies in your area.

Number of storage units sizes by company

Data as of 10/26/22. Average prices include online rates plus taxes and insurance. Applicable one-time administrative fees of approximately $25 not included. Size ranges, offers, and availability may vary by location and are subject to change.

Pro tips: Save money on your storage unit

Estimating the storage unit size you need will save you time and money. It’s a hassle to rent a unit and discover it’s not big enough for your boxes and larger items. And it’s no fun to realize you must dish out an extra $85 per month for a storage space that’s half-empty after you fill it up. If a small 5 x 5 storage unit is big enough for your belongings, there's no need to pay extra. 

Here are some tips to make picking a storage unit size easier—and cheaper:

Chat Boxes Icon
Storage tips for clothes

There are some essential storage tips for clothing you want to follow, no matter what size storage unit you get. Even the smallest-sized storage lockers can help you organize your bulky wardrobe items.

Compare the costs

Storage units often cost more than your stuff. For example, if you rent a unit to store a dresser, queen bed, and a few bookshelves, it will probably cost about $150 per month—or nearly $1,800 per year. At some point, it’s cheaper to rebuy everything later than it is to store it. Of course, that’s not helpful if you need to store irreplaceable items like yearbooks or legal documents. But you’d be surprised how often people spend more on storage units than their belongings are worth.

Identify your largest items

Sometimes you don’t have time to create a detailed inventory. Another option is to quickly estimate whether you need a small, medium, or large unit by identifying your longest and widest items. According to the storage unit size guide, anything over 10 feet long or wide rules out a small unit, while items over 15 feet bump you from a medium- to a large-sized unit.

Visit a storage facility

You can read all the storage unit guides in the world, but nothing’s as good as the real thing. Take an hour to visit a nearby storage facility. Go inside a few units and get a feel for how big they are and how many boxes will fit. A one-hour visit could save you hundreds of dollars.

Ask about specific sizes

Many storage unit companies have more available sizes than those published on their website. Call nearby storage facilities, give them your estimated square or cubic footage, and ask which units most closely match your needs. It’s like asking a shoe store to check in the back for your exact size. You could end up with a perfect fit.

Talk to several companies

Just because a storage unit facility has a medium-sized unit doesn’t mean that you can rent it. In many cases, tenants already occupy the spaces you want. But that’s not the end of the road. Search for storage unit companies near your zip code and check out their online sales. Chances are you’ll find the unit you need.

Consider moving containers

Don’t forget about portable storage options if you need only short-term storage. Most people use moving containers as a cheap alternative to rental trucks, but you can also store them at your home for a monthly fee. You may be able to save some money—and the headache of transporting your belongings to and from the storage facility.

A 1-800-PACK-RAT moving container is dropped off at a customer's home in Fort Leavenworth, Kansas.

Moving container companies like 1-800-PACK-RAT provide portable storage at your home for a monthly fee.

FAQs about storage unit sizes

The average square footage of a 3-bedroom house is approximately 1,200–1,400 square feet, according to recommends a medium-to-large-sized storage unit for the contents of a three-bedroom home.

The average storage unit size is approximately 10 x 10 feet (or 100 square feet). These medium-sized units cost around $150 per month and can often fit belongings from 1 to 3 bedrooms.

The size of the storage unit that you need depends on how much stuff you have. recommends you calculate the square footage of your belongings and then choose between a small (25–50 square feet), medium (75–150 square feet), or large (200–300 square feet) storage unit.

The largest standard storage unit size is 10 x 30 feet. These large units hold a capacity of 300 square feet (or 2,400 cubic feet) and cost approximately $277 per month.

Where can I find 10 x 10 storage?

You can find 10 x 10 storage at any major storage facility. recommends Extra Space Storage, CubeSmart, and

Which company has the most affordable storage space? has the most affordable storage space. says its average monthly price of approximately $160 is about $30 below the industry average.

What size storage unit do I need for major appliances?

You typically need a medium- or large-sized storage unit for major appliances. While most storage unit companies recommend large units for major appliances, you can often fit items like refrigerators, washers and dryers, and fridges in medium-sized units.

How much furniture fits in a storage unit?

The amount of furniture you can fit in a storage unit depends on the size of your self-storage space. For example, most couches are over seven feet long—or longer than many small storage units. recommends you compare the dimensions of your furniture with the measurements of your storage unit to estimate how much will fit.

Will a mattress set fit in a medium storage unit?

Yes, a mattress set will usually fit in a medium storage unit. recommends you compare the size of your mattress set with the dimensions of your storage unit.

What is the smallest storage unit size?

The smallest storage unit size is a storage locker that ranges from 9–25 square feet. They’re generally large enough to fit a few boxes and an end table.

Kurt Manwaring
Written by
Kurt Manwaring
Kurt Manwaring brings nearly a decade’s worth of research experience as a business consultant to the team. He specializes in taking complicated issues (like moving) and presenting them in a way that everyone can understand. His writing has been featured in hundreds of publications, including USA Today, Martha Stewart Living, Country Living, Good Housekeeping, Heavy, Slate, and Yahoo! Lifestyle. He brings a BS in sociology and an MPA (masters of public administration) to the Move team. He would love to hear about your moving experiences and questions at