Picking the right storage unit isn’t about counting your boxes; it's about understanding the total space your stuff will take up. It helps to think in real-world terms. For example, a small 25 sq ft unit is roughly the size of a large estate car's boot, while a 100 sq ft unit is more like a Luton van. Getting this comparison right is the key to finding your perfect fit without wasting money.

Choosing Your Storage Unit Size: A Quick Guide

Trying to figure out what size storage unit you need can feel like a bit of a guessing game. But honestly, it's simpler than it looks. The trick is to stop thinking about a perfect item-by-item list and start comparing the volume of your belongings to spaces you already know, like a room in your house or the size of a van. This gives you a much better mental picture of how much room you actually need.

Getting it right from the outset makes a massive difference. Go too small, and you’ll be in a frantic, last-minute panic trying to find a bigger space. Go too big, and you're literally paying for empty air. A well-chosen unit doesn't just save you money; it makes the whole process of packing, storing, and eventually getting to your things so much easier. If you need a hand with the packing side of things, our top tips on moving house packing are a real lifesaver.

Comparing Common Storage Unit Sizes

To help you nail that decision, let's break down the most common sizes with some practical examples. Each one is built for a different job, whether you're just stashing a few boxes or clearing out an entire family home.

• Small Units (Up to 50 sq ft): These are ideal for students needing to store their things over the summer, businesses archiving old documents, or for tucking away seasonal gear like garden furniture or the Christmas decorations.
• Medium Units (75 – 125 sq ft): This is our most popular range, and for good reason. It’s the go-to for anyone moving from a one or two-bedroom flat, offering plenty of space for furniture, white goods, and all those boxes.
• Large Units (150 sq ft and above): Think of these as your standard single garage. They're designed for the big jobs, like storing everything from a three or four-bedroom house during a renovation or a complicated move.

To give you an even clearer idea, here's a quick reference chart.

UK Storage Unit Size Quick Reference Chart

This table breaks down the common UK sizes, their dimensions, and what you can realistically expect to fit inside. We've even thrown in a vehicle analogy to help you visualise the space.

Unit Size (sq ft)	Typical Dimensions (ft)	What It Typically Holds	Vehicle Analogy
25 sq ft	5 x 5	Boxes, small furniture (e.g., armchair, chest of drawers), student belongings, garden tools.	Large estate car boot
50 sq ft	10 x 5	Contents of a studio flat or large shed. Furniture, appliances, and several boxes.	Transit van
75 sq ft	10 x 7.5	Contents of a one-bedroom flat. Includes major furniture, appliances, and many boxes.	Large transit van
100 sq ft	10 x 10	Contents of a two-bedroom flat or small house. Sofas, beds, wardrobes, etc.	Luton van
150 sq ft	15 x 10	Contents of a three-bedroom house. Perfect for house moves or major renovations.	Single garage
200+ sq ft	20 x 10 or larger	Contents of a four or five-bedroom house, including bulky items and outdoor furniture.	Large single garage

This chart is a great starting point for matching your needs to the right unit size.

As you can see, a crucial thing to remember is that doubling the dimensions of a unit actually quadruples its storage capacity. It's a simple but vital point when you're planning. While we're focused on storage units, it can be useful to see how other services think about volume. You might find some helpful ways of thinking about space in this comprehensive UK guide to skip sizes, for example.

Thinking in 3D: Understanding Unit Dimensions

When you're trying to figure out "what size storage unit do I need?", it's all too easy to just look at the floor plan. You see a number like 100 sq ft and immediately picture a 10-foot by 10-foot square on the ground. But that’s only seeing two-thirds of the picture. To really get a feel for how much a unit can hold, you've got to start thinking in three dimensions.

The real magic happens when you consider the total usable volume, measured in cubic feet. This number doesn't just look at the length and width; it brings the height into the equation. Most UK storage units have a generous ceiling height, usually around eight feet, and this vertical space is your secret weapon for packing smartly and getting the most for your money.

Think of it this way: imagine two rooms, both with a 10×10 foot floor. One has a standard eight-foot ceiling, but the other has a lofty twelve-foot ceiling. That extra height in the second room gives you a massive amount of extra storage potential. You can stack boxes higher, stand sofas on their end, and slide in tall items like bookcases or mattresses vertically. This is exactly why focusing on cubic feet, not just square feet, is so crucial.

From Square Feet to Cubic Reality

Thinking in volume helps you visualise how your belongings will actually Tetris together inside the unit. It’s the difference between laying everything out flat on the floor and strategically packing like a seasoned removals pro. By making the most of the full height, you can often fit the contents of a larger home into a smaller, more cost-effective unit.

To work out the cubic footage of any unit, the maths is simple. You just multiply its three dimensions:

• Length (ft) x Width (ft) x Height (ft) = Total Cubic Feet (cu ft)

So, for a standard 10×10 ft unit with an 8 ft ceiling, you’re looking at 800 cubic feet of packing space. That’s a huge volume to work with if you plan your packing right.

How to Estimate the Volume of Your Belongings

Right, so how do you work out how much cubic space your own stuff will take up? Don't worry, you don't need a degree in advanced mathematics. A few practical methods will give you a surprisingly accurate estimate.

1. Get the Tape Measure Out: Start with your biggest items. Measure the length, width, and height of your sofa, wardrobes, fridge, and bed frames. This gives you a solid baseline for the big, bulky pieces that will be the foundation of your packed unit.

2. Count Your Boxes: Group your moving boxes by size (small, medium, large) and simply count how many of each you have. You can usually find the cubic volume of a standard box online or printed on the packaging, then just multiply it by the number of boxes.

3. Use an Online Calculator: Many storage providers, including us here at MG Self Storage, have handy online storage calculators. These tools let you tick off your furniture and box quantities room-by-room to get an instant recommendation. It's a quick and painless way to get a solid estimate.

Taking a few minutes to estimate your total volume helps you sidestep the two most common (and costly) mistakes: underestimating and needing a stressful, last-minute upgrade, or overestimating and paying for empty space you'll never use.

The UK self-storage sector has been growing fast to keep up with demand, with total floorspace increasing by 7.2% in the last year alone to hit a massive 64.3 million square feet. This boom means more choice for you, but it also makes it even more important to make an informed decision. While the average unit size for personal storage is between 50 and 100 square feet, it's understanding your specific volume needs that ensures you pick the perfect fit. You can dive deeper into this trend by reading the full UK self storage industry report.

Switching your thinking from 2D to 3D turns guesswork into a proper plan, making sure you find the most efficient and economical answer to "what size storage unit do I need?".

Small Storage Units for Lighter Loads (10 to 50 sq ft)

Let's be honest, not everyone needs a storage unit the size of a double garage. Sometimes, you just need a bit of extra space for a lighter load, a temporary move, or to finally clear out that one cluttered room. This is where small storage units really shine.

These compact spaces, ranging from 10 to 50 square feet, are the perfect, cost-effective answer for things that don’t quite fit at home but are far too valuable to let go of. You only pay for what you actually need, which is always a smart move. They’re the unsung heroes for students between terms, small businesses archiving documents, or anyone wanting to reclaim their spare room from seasonal clutter.

The 10 sq ft Storage Locker: A Compact Solution

Think of a 10 sq ft unit as a spacious wardrobe or an old-school telephone box. It's the smallest option you'll typically find, designed for items you can neatly box up and stack.

While you won't get any large furniture in here, you’d be surprised how much it can hold if you think vertically. It’s a brilliant choice for decluttering or stashing away a small collection of personal belongings.

What typically fits in a 10 sq ft unit?

• Document Archives: Around 15-20 standard archive boxes, perfect for small business records.
• Student Belongings: A few suitcases, a desktop computer, textbooks, and several boxes of personal items.
• Sentimental Items: Photo albums, heirlooms, and other cherished belongings you want to keep safe.
• Hobby & Sports Gear: A set of golf clubs, tennis rackets, or your camping kit.

The 25 sq ft Unit: The Versatile Declutterer

Stepping up to a 25 sq ft unit (often 5×5 ft) gives you a bit more breathing room. This is one of our most popular small sizes because it hits that sweet spot between being compact and genuinely useful. Picture a large garden shed – it’s big enough for some small furniture items as well as your boxes.

This size is ideal for clearing out a single room, storing everything from your shed, or tackling a major wardrobe clear-out. For many people wondering "what size storage unit do I need?", this is the perfect place to start for smaller projects.

For example, a sports enthusiast could easily fit a couple of bicycles, skiing equipment, and camping gear, freeing up a ton of space at home during the off-season.

The 50 sq ft Unit: For Studio Flats and More

The 50 sq ft unit is the real workhorse of the small storage world. Usually measuring 10×5 ft, this space is about the size of a large walk-in wardrobe and can comfortably hold the contents of a studio or small one-bedroom flat. It’s a hugely popular choice for people moving between smaller homes or doing minor renovations.

If you’re moving out of a small flat, you can generally fit a double bed, a small sofa, a chest of drawers, a TV, and around 20-30 boxes. It’s the go-to solution when you need a decent amount of space without jumping up to a medium or large unit.

A great tip for a 50 sq ft unit is to organise it so you can leave a small walkway down the middle. It makes a world of difference when you need to get to something at the back without unpacking the whole thing.

To give you a clearer idea, here's what you could realistically store in a 50 sq ft unit:

• Double bed frame and mattress
• A two-seater sofa
• Chest of drawers or a small wardrobe
• Coffee table and bedside tables
• Small dining table and two chairs
• Appliances like a microwave or television
• Up to 30 medium-sized moving boxes

By picturing your belongings in these spaces, you can pick the right small unit with confidence, getting a secure and practical space without paying for anything you don’t need.

Medium Storage Units for Big Life Changes (75 to 125 sq ft)

Now we’re moving into the real workhorses of the storage world: the medium-sized units. Ranging from 75 to 125 square feet, these are the go-to choice when life throws something big your way. Think house moves, major home renovations, or even combining two households into one.

This is where you get some serious space without having to commit to a massive, garage-sized unit. It’s no wonder they’re so popular with families and businesses navigating a bit of a transition. They just hit that sweet spot between having enough room for everything and not breaking the bank.

The 75 sq ft Unit: A One-Bedroom Flat Solution

A 75 sq ft unit is a fantastic choice, often measuring about 10×7.5 ft. This is usually more than enough space to pack away the entire contents of a one-bedroom, or even a smaller two-bedroom, flat. It’s the perfect temporary home for all your belongings while you’re between places or gutting the house for a big project.

This is the size where you can comfortably fit in larger furniture that the smaller units just can’t handle. It gives you enough breathing room to stack things properly so everything stays safe, sound, and easy to get to.

What fits in a 75 sq ft unit?

• Big living room furniture like sofas, armchairs, and a coffee table.
• Bedroom essentials, including a double bed, wardrobe, and chest of drawers.
• Kitchen appliances like a fridge-freezer and a washing machine.
• A small dining set and stacks of moving boxes.

The 100 sq ft Unit: The Go-To for a Two-Bedroom House

The 100 sq ft unit is what many people picture when they think of self storage. With classic 10×10 ft dimensions, it's easy to visualise – roughly the size of a small single garage. This makes it the industry standard for the average two-bedroom house move.

Imagine you're tearing out your kitchen and living room. A 100 sq ft unit lets you get all the furniture, appliances, and packed-up bits and pieces completely out of the way. Everything stays clean, safe, and away from the builders' dust.

A little tip for a space this size: planning is everything. Pop the big, heavy stuff at the back and on the floor to create a solid base. Keep anything you might need to grab—like important paperwork or seasonal gear—right near the front.

The 125 sq ft Unit: For Growing Families and Businesses

Stepping up to 125 sq ft gives you that bit of extra elbow room for larger homes or a growing business. This space can often swallow the contents of a two-bedroom house plus the garage and shed, or even a small three-bed property. It’s perfect for that bulky garden furniture, sports equipment, or extensive collections that need a home.

For a small business, this size can be a total game-changer. An online seller, for instance, could use it to hold several pallets of stock, manage seasonal inventory, and keep all their shipping supplies organised without cluttering up their home or paying for pricey commercial property.

The rising popularity of these versatile units really reflects what’s happening across the country. The UK self storage market is already worth around £1 billion and is expected to more than double by 2033, driven by more people living in cities and smaller homes. It just shows how essential this kind of flexible, off-site space is becoming. You can dig into the numbers on the UK self storage market growth on OpenPR.com.

So, when you’re asking yourself "what size storage unit do I need?" for a major life event, one of these medium sizes is very often the most practical and sensible answer.

Large Storage Units for Major Moves (150 sq ft and Up)

When you’re staring down the barrel of a major life event—moving the entire family home, launching into a full-scale renovation, or managing a serious amount of business inventory—you need a storage solution that can handle the load. This is where our large storage units step in, offering expansive, garage-sized spaces for the biggest jobs.

These units, starting from 150 square feet and climbing up to 200 sq ft and beyond, are designed to hold the contents of a three or four-bedroom house. We’re talking sofas, white goods, garden tools, and stacks upon stacks of boxes. If you're asking yourself, "what size storage unit do I need for a whole house?", this is almost certainly your answer.

The 150 sq ft Unit: The Single Garage Equivalent

To get a real feel for a 150 sq ft unit, just picture a standard single-car garage. With dimensions typically around 15×10 ft, it gives you a huge amount of floor space and, just as importantly, plenty of height for stacking. This size is the go-to for families moving out of an average three-bedroom home.

It can comfortably swallow all the essentials of a family home, so you don’t have to leave anything behind.

What typically fits in a 150 sq ft unit?

• Large Furniture: Think multiple sofas, armchairs, a dining table and chairs, wardrobes, and bed frames.
• Major Appliances: Fridge-freezers, washing machines, tumble dryers, and dishwashers will all fit.
• Outdoor and Garage Items: Lawnmowers, bikes, patio furniture, and tool chests.
• Boxes Galore: You can easily get 50-60 medium to large moving boxes in alongside your bigger items.

This size is also a lifesaver for business owners who need to store bulk stock, equipment, or archives without the high cost of commercial warehouse space.

The 200 sq ft Unit and Larger: For Maximum Capacity

When even a single garage isn't quite big enough, a 200 sq ft unit (often 20×10 ft) offers total peace of mind. This is the solution for storing everything from a four or five-bedroom house, or for anyone with bulky hobby gear like boats or jet skis.

These vast spaces are also a massive asset for commercial clients. An e-commerce business could hold entire product lines, while a tradesperson could securely store tools, materials, and even a work van. If you’re trying to understand why self-storage in Exeter is the answer, our article offers some great real-world examples.

Organising a Large Storage Unit Effectively

Having all that space is one thing, but using it wisely is another. A badly organised large unit can be just as frustrating as one that's too small, especially when the one thing you need is buried right at the back.

The biggest mistake people make with large units is packing them wall-to-wall. Always leave a central walkway from the door to the back. This one simple trick transforms your unit from a cluttered box into an accessible archive.

Here are a few tips to keep your large unit organised:

1. Map It Out: Before you move anything in, sketch out a quick plan. Put the bulkiest, heaviest items at the back and along the sides to create a solid base.
2. Label Everything Clearly: Don't just scribble on the top of the box. Label it on multiple sides with its contents and which room it belongs to. It’ll save you a world of pain later.
3. Prioritise Access: Keep things you’ll need to get to most often near the front, just off your central walkway. Think seasonal decorations, important paperwork, or specific tools for a project.

A little planning goes a long way. It ensures your large unit works for you, giving you a secure, organised space for everything life throws your way.

Common Mistakes to Avoid When Choosing a Unit

Choosing the right storage unit can save you a whole lot of money and stress down the line. But we’ve seen a few common slip-ups turn a simple task into a proper headache. Nailing your choice means sidestepping these classic pitfalls.

The biggest error we see is people underestimating just how much stuff they actually have. It’s so easy to eyeball a room and take a guess, but our belongings almost always take up more space than we think. This often leads to a frantic, last-minute panic on moving day, forcing an upgrade to a bigger, pricier unit.

On the flip side, overestimating and paying for a half-empty unit is like literally throwing money away. You’re paying to store thin air, and that’s never a good deal. The sweet spot is finding that perfect balance where everything fits comfortably without being a squeeze or a waste of space.

Forgetting to Plan for Access

This one’s a classic. You’ve managed to get everything in, but you’ve packed it so tightly you can’t get to a single thing. People often focus on filling every last inch, completely forgetting they might need to grab a box from the very back.

Without a little walkway, getting to your items becomes an impossible game of Tetris. A bit of forethought here makes a world of difference. As you’re loading everything in, make sure to leave a clear path down the middle. This simple step transforms a chaotic pile into an organised, accessible space. Planning the layout is just as crucial as packing the boxes, and you can find some great tips in our ultimate moving house packing checklist.

Choosing Solely Based on Price

It’s always tempting to just grab the cheapest option, but this can be a false economy. Of course, the price is important, but it shouldn't be the only thing you look at. A bargain-basement unit that’s miles out of your way or has dodgy security isn’t much of a bargain at all.

Think about these other factors alongside the monthly cost:

• Location: How much time and fuel will you spend driving back and forth? A slightly more expensive unit closer to home could actually save you money.
• Security: Does the place have proper CCTV, gated access, and decent lighting? Your peace of mind is worth a lot.
• Accessibility: Can you get to your unit 24/7, or are the opening hours restrictive? Make sure it works with your schedule.

Pro Tip: Always pop down to the facility before you commit. It lets you see the security for yourself, get a proper feel for the unit sizes, and make a decision you feel confident about.

Keep in mind that demand can also affect availability and price. For example, in built-up areas like the South East, which is expected to see a 6.3% increase in storage space, smaller units are often snapped up first. This is because people living in flats and smaller homes are always on the lookout for a bit of extra room.

Your Questions Answered About Storage Sizes

Even after breaking it all down, you might still have a few questions rattling around. It's completely normal. To help you feel confident in your decision, we've pulled together some of the most common queries we get from our customers here in Exeter.

Should I Get a Bigger Unit Just in Case?

Honestly, it’s a smart move. We nearly always recommend going one size up if you're unsure. That little bit of extra room isn't just a safety net; it lets you leave a small aisle so you can actually get to the boxes at the back without unpacking everything.

It also saves you the massive headache of realising on moving day that you've run out of space. The slight extra cost is usually well worth the peace of mind.

How Do I Plan for Bulky or Oddly Shaped Items?

For big things like sofas, wardrobes, or that awkwardly shaped exercise bike, your tape measure is your best mate. Get the dimensions of your largest items first – length, width, and height.

Don’t forget to think vertically! Many people stand their sofas on end to free up a huge amount of floor space, but for that to work, you need to know your unit’s ceiling height. It's all about using the full cubic volume, not just the square footage.

A lot of people only think about the floor plan. Remembering to use the full height of your unit is one of the most essential tips for choosing a self storage unit because it effectively doubles your usable space.

Can I Change My Storage Unit Size Later On?

Absolutely. Most reputable UK facilities, including us, are pretty flexible. If you start moving in and realise it’s just not going to work – whether it's too big or too small – you can usually switch to a different size, as long as one is available.

It's always a good idea to double-check the facility's policy on this before you sign on the dotted line, just so you know exactly where you stand.

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Ready to find the perfect storage solution in Exeter? The friendly team at MG Self Storage is here to help you choose the ideal unit size for your needs, ensuring you get a secure, clean, and accessible space. Find your perfect unit with us today