How to Estimate the Storage Unit Size You Need

Kurt Manwaring
Researcher & Writer
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Published on May 26, 2021
7 min read

At a glance

The price difference between small and medium storage units is more than $800 per year—even if you use one of the best self-storage companies. That means it pays to estimate the 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.

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, 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.

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 $840 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 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.
  2. Cubic feet (cu. ft.). Multiply the length, width, and height of your belongings. If they 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. Another option is to individually measure each item’s length, width, and height. Anything works so long as you have an estimate of your square or cubic footage.

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.

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 large enough to store your stuff—but not so big 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.

Storage units and pricing by company

Company name
What to know
# of storage unit sizes
Average monthly cost
Extra Space StorageBest overall8+$220
CubeSmartLots of sizes11+$160
Simply Self StorageLow prices8+$160
U-HaulWide availability9+$160
Life StorageGreat customer service9+$200

Data as of 2/26/21. 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. And it’s no fun to realize you must dish out an extra $70 per month for a storage space that’s half-empty after you fill it up.

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

  • 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 $160 per month—or nearly $2,000 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. 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.

How to estimate the storage unit size you need FAQ

What is the average square footage of a three-bedroom house?

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.

How big is a 5 x 5 storage unit?

A 5 x 5 storage unit is 5 feet long and 5 feet wide (or 25 square feet). The average cost for one of these small storage spaces is approximately $90 per month.

How big is a 10 x 10 storage unit?

A 10 x 10 storage unit is 10 feet long and 10 feet wide (or 100 square feet). The average cost for one of these medium-sized self-storage units is approximately $160 per month.

How big are storage units?

Storage units range from 3 x 3 feet (small) to 10 x 30 feet (large). In some cases, you can find units up to 50 feet long designed for oversized recreational vehicles. Prices vary, but you typically pay more for larger storage spaces than smaller ones.

What is the average storage unit size?

The average storage unit size is approximately 10 x 10 feet (or 100 square feet). These medium-sized units cost around $160 per month and can often fit belongings from 1 to 3 bedrooms.

What size storage do I need?

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.

What is the largest standard storage unit size?

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 $290 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 Simply Self Storage.

What is the average cost of a 5 x 5 storage unit?

The average cost of a 5 x 5 storage unit is approximately $90 per month. These small 25-square-foot units often fit many belongings from one small bedroom.

Which company has the most affordable storage space?

Simply Self Storage has the most affordable storage space. says its average monthly price of approximately $160 is about $20 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.

How big are storage lockers?

Storage lockers range from 9–25 square feet and are the smallest storage spaces available for rent. These units are generally half the size of a small closet and often fit a few boxes and an end table.

Do I need climate-controlled storage for document storage?

Yes, you likely need climate-controlled storage for document storage. Climate-controlled storage prevents damage to valuable documents and photographs by monitoring your unit’s humidity and temperature levels.

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