Sofa Size Calculator
A sofa that fills every inch of the wall it sits against leaves no room to walk past or fit a side table, while an undersized one can leave a living room feeling sparse. Enter the length of your wall below to see the largest sofa that will fit comfortably.
Work out the largest sofa that will fit
Enter the length of the wall you want to place the sofa against.
Leaving 0.45m clear on each side for walking past and a side table, the largest sofa you should fit is:
up to 3.10m long
That's roughly a Large corner or modular sofa.
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- Sturdy beech wood frame with tapered legs
- Durable, easy-clean polyester weave fabric
- UK-built and delivered
Cons
- Flat-pack assembly takes two people
- Faux leather
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Pros
- Wipe-clean faux leather
- Compact 2-seater footprint for flats
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Cons
- Firmer cushioning than fabric sofas
- Fewer colourways than some rivals — no navy option
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- Sturdy wood frame with soft-touch velvet upholstery
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Cons
- Long lead time for delivery
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Frequently asked questions
How much clearance should I leave around a sofa?
A good minimum is around 45cm on each side for a side table, lamp or simply walking space, so the sofa doesn't feel jammed wall-to-wall. In a room that also needs to function as a walkway, allow more.
Should I measure my doorways before buying a large sofa?
Yes — a sofa that fits the room perfectly is no good if it can't get through the front door, hallway corners, or stairwell. Check the delivery route width and any tight turns, not just the final room dimensions.
Is a corner sofa always better value for space?
Corner sofas maximise seating along two walls and can suit open-plan rooms well, but they take up a large single footprint that's hard to reposition later. In a squarer or smaller room, two smaller sofas or a 3-seater plus armchair setup can feel more flexible.
How far should a sofa be from the TV?
As a rough guide, sit around 1.5 to 2.5 times the TV's screen size away (in the same units) for comfortable viewing — for example, roughly 2-3m back from a 55 inch TV.
How this calculator works
The calculator takes the length of the wall you want to place the sofa against and subtracts a clearance allowance of 45cm on each side. This clearance is for walking past the sofa, fitting a side table or lamp, and preventing the sofa from feeling jammed wall-to-wall. The result is the maximum sofa length that will fit comfortably.
The calculator then matches that maximum length to a standard sofa size band: 2-seater (up to 1.6m), 2.5/3-seater (up to 2.0m), 3-seater (up to 2.4m), 3.5-seater or small corner (up to 3.0m), or large corner/modular (over 3.0m). These are typical UK sofa sizes, but always check the exact dimensions of the model you're buying — some 3-seaters measure 2.2m or more.
Typical UK sofa sizes
| Sofa type | Typical length | Minimum wall length (with clearance) | Seats | Typical room |
|---|---|---|---|---|
| Compact 2-seater | 1.4-1.6m | 2.3m | 2 | Small flat, bedroom, snug |
| Standard 2-seater | 1.6-1.8m | 2.7m | 2 | Small living room, flat |
| 2.5/3-seater | 1.9-2.1m | 3.0m | 3 | Standard living room |
| Large 3-seater | 2.2-2.4m | 3.3m | 3 | Medium-large living room |
| 3.5-seater | 2.5-2.8m | 3.7m | 3-4 | Large living room, open-plan |
| Small corner sofa | 2.0-2.4m | 3.0m | 3-4 | Open-plan, L-shaped room |
| Large corner sofa | 2.8-3.2m | 3.7m | 5-6 | Large open-plan, L-shaped |
Worked example: A 3.5m wall
A wall 3.5m long with 45cm clearance on each side gives a maximum sofa length of 3.5 - 0.45 - 0.45 = 2.6m. This fits a large 3-seater (up to 2.4m) or a small 3.5-seater (up to 2.8m). A standard 3-seater at 2.2m would fit comfortably with 40cm of clearance on each side, leaving room for a side table and lamp.
If the same 3.5m wall is in a room that also needs to function as a walkway, you might increase the clearance to 60cm on each side, reducing the maximum sofa length to 3.5 - 0.6 - 0.6 = 2.3m. This rules out a 3.5-seater and limits you to a standard 3-seater or smaller. Always measure the actual traffic flow through the room before buying.
Common mistakes when choosing sofa size
- Buying a sofa based on the room's total width instead of the wall length. A sofa sits against a specific wall, not across the room. Measure the exact wall you want to place it against, not the room's widest point.
- Forgetting to account for other furniture. A sofa against a 3.5m wall sounds fine, but if you also need a TV stand, sideboard, or bookshelf in the same room, those items eat into the available space. Sketch a rough floor plan to check everything fits.
- Not checking the delivery route. A large sofa that fits the room perfectly is useless if it can't get through the front door, hallway corners, or stairwell. Measure all narrow points on the delivery route before buying, not just the final room dimensions.
- Assuming a corner sofa saves space. Corner sofas maximise seating along two walls, but they take up a large, inflexible footprint. In a small or square room, two smaller sofas or a 3-seater plus armchair can feel more flexible and leave better traffic flow.
What to look for when buying a sofa
Frame construction determines how long a sofa lasts. A solid hardwood frame (oak, beech, or similar) with mortise-and-tenon joints is the gold standard — it won't creak, wobble or fall apart after a few years. Avoid sofas with particleboard or softwood frames, which can sag and fail within 5-10 years. Look for a guarantee of at least 10 years on the frame.
Cushion filling affects both comfort and maintenance. Foam cushions are firm, supportive and hold their shape well, but they can feel hot in summer and don't mould to your body. Feather or down cushions are softer and more luxurious, but they need regular plumping and can feel flat until broken in. A hybrid — foam core with a feather wrap — gives the best of both worlds for most households.
Finally, think about the fabric. Leather is durable, easy to clean and ages well, but it's cold in winter, sticky in summer, and expensive. Fabric sofas are more comfortable year-round and come in a wider range of colours and textures, but they're harder to clean if spilled on. Look for removable, machine-washable covers if you have children or pets — it's a lifesaver when something gets spilt.
More questions answered
How much clearance should I leave around a sofa?
A good minimum is around 45cm on each side for a side table, lamp or simply walking space, so the sofa doesn't feel jammed wall-to-wall. In a room that also needs to function as a walkway, allow more.
Should I measure my doorways before buying a large sofa?
Yes — a sofa that fits the room perfectly is no good if it can't get through the front door, hallway corners, or stairwell. Check the delivery route width and any tight turns, not just the final room dimensions.
Is a corner sofa always better value for space?
Corner sofas maximise seating along two walls and can suit open-plan rooms well, but they take up a large single footprint that's hard to reposition later. In a squarer or smaller room, two smaller sofas or a 3-seater plus armchair setup can feel more flexible.
How far should a sofa be from the TV?
As a rough guide, sit around 1.5 to 2.5 times the TV's screen size away (in the same units) for comfortable viewing — for example, roughly 2-3m back from a 55 inch TV.
What's the difference between a 3-seater and a 3.5-seater?
A standard 3-seater is typically 2.0-2.2m long and seats three adults comfortably. A 3.5-seater is 2.4-2.8m long and gives a bit more room per person, or space for a fourth person on the end. The 'extra' half-seat is mostly about width rather than length — a 3.5-seater is deeper and wider, not just longer.
Should I buy a sofa bed if I don't have a spare room?
Sofa beds are useful if you occasional guests but no dedicated guest room, but they're heavier, bulkier and less comfortable as a sofa than a standard model. The mechanism can also fail over time. If you have space, a pull-out sofa bed or a daybed is often more versatile. If you only need guest accommodation a few times a year, an air mattress or a spare bed in a cupboard is cheaper and less intrusive.
How long should a sofa last?
A good quality sofa with a solid hardwood frame should last 10-15 years or more with proper care. The cushions will need replacing or re-foaming after 5-8 years depending on use. Budget sofas with particleboard frames may need replacing in 3-5 years. Look for a long frame guarantee — 10 years is the minimum for a sofa you expect to keep for a decade.
What sofa size do I need for a small living room?
For a small living room (under 20m²), a compact 2-seater (1.4-1.6m) or a standard 2-seater (1.6-1.8m) is usually the right call. It leaves enough room for a coffee table, TV stand and walking space without feeling cramped. If you occasionally need more seating, add one or two armchairs that can be moved around rather than buying a large fixed sofa.