A studio flat or a couple of rooms of furniture fits a 5ft unit (35 sq ft). A one or two-bed home needs a 10ft unit (75 sq ft). A three-bed house needs a 20ft unit (150 sq ft), and a four or five-bed house with a garage’s worth of extras needs a 40ft unit (300 sq ft). Most people underestimate what they own by around one size, so if you’re between two, size up.
Here’s the thing nobody tells you before you book a storage unit: almost everyone guesses too small. Not because they’re bad at maths, but because it’s genuinely hard to picture how a house full of furniture, boxes, and “we’ll sort that later” items compresses down into a container. You’ve never had to stack your own life into a box before, so why would you be good at it on the first try?
This guide fixes that. We’ll go through what actually fits in each of our four unit sizes, room by room, with real numbers rather than vague guesses. We’re a container storage company with two sites, one in Birmingham and one in Stoke-on-Trent, so everything below is based on what we watch people load in and out of our units every week, not a generic size chart copied from somewhere else.
Key takeaways
- A 5ft unit (35 sq ft) suits a studio flat or the contents of one or two rooms
- A 10ft unit (75 sq ft) is the most commonly booked size and fits a one to two-bed home
- A 20ft unit (150 sq ft) holds a three-bed house including white goods and garden furniture
- A 40ft unit (300 sq ft) covers a four or five-bed house, or a garage and loft combined
- The UK self storage average is £29.13 per square foot per year, but container storage in the West Midlands and Staffordshire typically undercuts city-centre indoor facilities considerably
What storage container sizes are available?
A storage container size, in the self storage world, refers to the length of the physical shipping container your goods sit inside, not the floor plan of a purpose-built room. We stock four: 5ft, 10ft, 20ft, and 40ft. Each is roughly 7ft wide and 7.5 to 8ft tall, so the “5ft” or “20ft” figure you see quoted is the length, and the square footage that gets compared across the industry (35, 75, 150, and 300 sq ft) is the length multiplied by the width.
This matters because container storage packs differently to a purpose-built storage room. A container is a single rectangular box with one set of doors at the end, so you load it like a removal van, not a lock-up: heavy and awkward items go in first, along the back wall, and everything else builds forward from there. Keep that in mind as you read the sizes below, because it changes how much you can realistically fit compared with a squarer room of the same square footage.
5ft storage unit: what fits in 35 sq ft?
A 5ft container gives you roughly 35 sq ft of floor space, similar in footprint to a small box room or a large garden shed. Realistically, it holds the contents of one to two rooms, which makes it the right call for:
- A studio flat’s worth of furniture and boxes
- Excess furniture from one room during a renovation
- A single bedroom’s contents while you’re between houses
- Seasonal items: Christmas decorations, camping gear, a couple of bikes
- Document boxes and archive storage for a small business
Derived example: a single bed frame and mattress (roughly 130cm x 190cm), a two-seater sofa (around 150cm wide), a small fridge freezer (60cm wide, up to 180cm tall), and 15 to 20 medium moving boxes will comfortably fill a 5ft unit with a little room to spare for boxes stacked to head height along one wall. Add a wardrobe and you’re at capacity.
Who this isn’t for: if you’re storing the contents of more than one bedroom, or you own a sofa longer than about two metres, you’ll be back within a month asking to upsize. We’d rather tell you that now than sell you the smaller unit and have you pay for two moves.
10ft storage unit: what fits in 75 sq ft?
This is our most booked size, and for good reason: 75 sq ft is close to what a one-bedroom flat or a small two-bed terrace actually needs. Think of it as roughly half the floor space of a single garage, but with more usable height because you’re not working around a sloped roof or a garage door track.
Typical contents of a 10ft container:
- A double bed, wardrobe, chest of drawers, and bedside tables
- A three-seater sofa and armchair
- A dining table with four chairs
- A full-size fridge freezer and washing machine
- 25 to 35 boxes
Derived example: a standard UK fridge freezer runs 60 to 70cm wide and up to 180cm tall. A three-seater sofa is typically 190 to 220cm long. Stack those against one wall, put the bed frame and mattress flat against the opposite side, and you’ve used maybe 40% of a 10ft unit’s floor space before a single box goes in, which is exactly why this size copes with a full one-bed flat and still has room for the boxes.
Who this isn’t for: a genuine three-bed house won’t fit here even if you’re a minimalist. You’ll get the bedroom furniture in and then run out of room for the living room and kitchen. Go up a size rather than trying to force it.
20ft storage unit: what fits in 150 sq ft?
A 20ft container gives you 150 sq ft, which is roughly the footprint of a single garage with a bit of extra length. This is where most full house moves land, specifically a three-bedroom semi with the usual mix of furniture, white goods, and the garden stuff that never quite fits anywhere else.
What we typically see fill a 20ft unit:
- Three bedrooms’ worth of beds, wardrobes, and drawers
- A full living room suite: sofa, armchairs, TV unit, coffee table
- Dining furniture for six
- Fridge freezer, washing machine, tumble dryer
- Garden furniture, a lawnmower, and a shed’s worth of tools
- 40 to 60 boxes
Derived example: a washing machine and tumble dryer stacked or placed side by side take up roughly 1.2 to 1.4 square metres of floor space between them. Add a fridge freezer at another 0.5 square metres, and white goods alone account for around 13% of a 20ft unit’s total floor area, leaving the rest genuinely free for furniture and boxes rather than being eaten up before you start.
Who this isn’t for: if you’re storing a five-bed detached house with a fully kitted-out garage and a workshop’s worth of tools on top, you’ll likely need the 40ft, or you’ll be stacking boxes to the ceiling and struggling to reach anything at the back.
40ft storage unit: what fits in 300 sq ft?
The largest container we offer, at 300 sq ft, comfortably covers a four to five-bedroom house including the contents of a garage or loft. This is the size we’d point a business toward too, if stock, machinery, or a fleet’s worth of equipment needs housing rather than a household move.
Common uses for a 40ft unit:
- A full four or five-bed house move, including all white goods
- Garage contents: tools, bikes, a motorbike, sports equipment
- Business stock for a growing online retailer
- Building materials and site equipment for a small trades business
- Vehicle storage alongside household goods, where site layout allows
Derived example: at 300 sq ft you have roughly the floor area of a large double garage. A family of five’s furniture typically runs to 90 to 110 boxes on top of the large items, according to the packing estimates most UK removal firms quote for a similar-sized house, so a 40ft unit is sized with that volume in mind rather than as an arbitrary jump from the 20ft.
Who this isn’t for: a single professional storing a one-bed flat’s contents while renting somewhere new. You’ll pay for a lot of empty space. Start smaller and upsize if you need to; most container storage providers, us included, make that straightforward.
Storage unit size guide table: which size do you need?
| Property or situation | Recommended unit | Approx. floor space | What’s included |
|---|---|---|---|
| Studio flat, 1 room | 5ft | 35 sq ft | Bed, sofa, small fridge, 15-20 boxes |
| 1-2 bed flat or house | 10ft | 75 sq ft | Full bedroom, sofa, dining set, white goods |
| 3 bed house | 20ft | 150 sq ft | 3 bedrooms, living room, white goods, garden items |
| 4-5 bed house, garage | 40ft | 300 sq ft | Full house plus garage or loft contents |
| Tradesperson tools and materials | 10ft-20ft | 75-150 sq ft | Tools, ladders, stock, machinery |
| Online seller stock | 10ft-40ft | 75-300 sq ft | Scales with inventory, easy to upsize |
How much does self storage cost in Birmingham and Stoke-on-Trent?
The Self Storage Association UK’s 2025 Annual Industry Report puts the national average at £29.13 per square foot, per year, across all storage types and regions. That figure covers everything from central London indoor facilities to rural container yards, so it isn’t a useful number on its own. What matters is the regional and format breakdown underneath it.
Storage in London runs well above that national average; industry pricing data from HOLD Storage and Happy2Move both put central London at over £4 per square foot per month, with the West Midlands and similar regions sitting closer to half that. Container storage, specifically, tends to undercut purpose-built indoor facilities further still, because the build cost and running cost of a converted shipping container site is lower than a multi-storey climate-controlled building, and that saving typically gets passed on in the price.
We run current promotions across both branches, including a 50% discount for the first two or three months and offers of up to £150 off, usually on selected 10ft and 20ft units for new customers. If you want an exact price for your size and site, call the branch direct: Birmingham on 0121 312 3907, or Stoke-on-Trent on 01782 906 565.
Container storage vs a spare room, garage, or attic
Before you book anything, it’s worth being honest about the alternative, because storage isn’t always the right answer.
A garage works if it’s genuinely dry, and if you don’t need the car space back. The problem is condensation: an unheated, unventilated garage in the Midlands winter will damage cardboard boxes, upholstery, and anything with a circuit board over a few months, in a way a purpose-built storage unit won’t.
A loft is fine for lightweight, low-value items you rarely need, and it’s free. It’s a poor choice for anything heavy (the joists usually aren’t rated for it), for furniture that won’t fit through the hatch, and for anything you’ll need access to regularly, because loft ladders and low headroom make repeated trips unpleasant fast.
A spare room costs you the room. If you’re renting it out, selling the house, or just want the space back for its actual purpose, storage is nearly always cheaper than the opportunity cost of a room you can’t use.
Who storage isn’t for: if what you’re storing is worth less than three or four months of unit rental, and you’re not attached to it, selling or donating it is usually the better call. Storage makes sense when the value of the item, or the value of the space you free up, clearly exceeds the monthly cost.
Common mistakes people make when choosing a storage unit size
Sizing for what you’re storing today, not what’s coming. If you’re mid-move, you’ll accumulate more before it’s done. Leave 10-15% headroom.
Ignoring container access when planning the layout. A container has one entry point, unlike a squarer indoor room you can walk around. Plan to load heavy, rarely-needed items first and toward the back, and keep anything you’ll need mid-storage near the door.
Assuming smaller always means cheaper. A unit that’s too small means an awkward second move to a bigger one later, plus the hassle of re-hiring a van. Getting the size right the first time is usually the cheaper outcome overall.
Forgetting white goods need defrosting and drying first. A fridge freezer stored wet or with residual ice will develop mould in storage. Defrost and dry it out 24 hours before it goes in.
Not asking about drive-up access. Ground floor, drive-up units, which is what we offer at both our sites, mean you load straight from your vehicle without stairs, lifts, or long internal corridors. That alone changes how long a house move’s worth of loading actually takes.
What actually protects your belongings in storage?
Size is only half the picture. What happens to your things once they’re in the unit matters just as much, and it’s the part most size guides skip entirely.
Container storage units are built from the same steel that ships goods across oceans, so they’re inherently weatherproof and secure by design, without extra structural work. At both our Birmingham and Stoke-on-Trent sites, every unit sits within a gated, secured premises with 24 hour manned security and CCTV monitoring around the clock. That’s a genuinely uncommon combination in UK self storage; most facilities offer CCTV and a keypad gate, but round-the-clock manned staff on-site is far less common and worth checking for specifically when you compare providers, because an empty yard at 2am with only cameras watching is a different level of security to one with a person actually there.
Who this storage guide isn’t for
If you need climate or humidity control for specific items, such as fine art, wine, vintage instruments, or archival documents with strict conservation requirements, a standard container unit isn’t the right fit and you should look for a specialist facility. Standard container storage suits the overwhelming majority of household and business goods well, but it’s worth being upfront about where it doesn’t.
Last updated: July 2026. Prices and offers correct at time of writing and subject to change; contact your local branch to confirm current rates.
About U Store U Lock: we operate two container self storage sites in the West Midlands and Staffordshire, in Birmingham and Stoke-on-Trent, offering 5ft, 10ft, 20ft, and 40ft units with drive-up access, 24 hour manned security, and CCTV. Speak to the Birmingham team on 0121 312 3907 or the Stoke-on-Trent team on 01782 906 565.
