# Use This Calculation to Figure Out What Size Storage Unit You Need, Says One Pro

published Feb 18, 2023
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Running out of closet space? If decluttering isn’t the answer to your organizational needs, you might be wondering if it’s worth it to rent a storage unit for your extra stuff.

Self-storage isn’t a bad plan for storing key seasonal items you won’t be touching for months at a time. And it’s actually a great idea if you’re getting ready to sell your home and would prefer not to live among stacks of teetering boxes in the meantime.

But how much storage space do you need? It’s not exactly the riddle of the Sphinx, but underestimating the size of the storage space is one of the biggest mistakes customers make, according to Nancy Zafrani, general manager of Oz Moving & Storage in New York City. It’s all well and good to pile those boxes up — more on that in a moment — but not if you need frequent access to something you’ve stowed well out of reach.

## Don’t Estimate, Calculate

While we usually talk of real estate in terms of square footage, it’s all about cubic feet in the storage world. Some self-storage companies include a storage space calculator on their website, but it’s easy to do on your own, says Zafrani. Make a list of the items you plan to store, then multiply their length by width by height to find the cubic footage. (You can also use an online cubic footage calculator.)

Once you’ve measured the items you plan to put in storage, Zafrani says, “I recommend adding a 10 to 20 percent buffer to that figure.” So if you’ve got 400 cubic feet of stuff, make it 440. She says that most storage rooms are eight feet tall, so divide 440 by 8, and you’ll need a 55-square-foot (that’s length by width) footprint for storage.

But do remember the height capacity in your storage space. “Storage is meant to be stacked, Zafrani says. This is where packing things in sturdy boxes of roughly the same size will be helpful in keeping those piles stale. Of course, if you are physically unable to stack or access boxes once they are stacked, choose a larger storage unit, she says.

## Pack with a Plan

Before you start stacking boxes in your storage unit, Zafrani has a bit of advice: “Always remember: The things you put in first will be the least accessible.”

This advice might not apply if you are only planning two trips to the storage facility: one to load and one to empty. But if you’ll be accessing it regularly and want some breathing room to organize or sort your belongings, you’ll need a bigger space so you can actually walk around, she explains.

If you’ve run the numbers and have concluded you do need a lot of space, Zafrani suggests getting two rooms — one for items you don’t need and one for items you still need to access. “This will allow you to really pack tightly in the room that you will not need to access and leaves more room to get around in the one you will need to access more frequently,” she says. For the storage unit you’ll be accessing, Zafrani recommends leaving behind a step ladder so you can stack and restack boxes more easily.

And if after all that calculating and stacking you’ve found you have indeed underestimated your storage needs, it’s not a disaster. “Most self-storage facilities will also have available small units, which you can add on in case you underestimate,” Zafrani says.