What Is a Sofa Bed? How to Choose One in 6 Steps

A sofa bed gives you somewhere comfortable to sit every day and a proper bed for guests at night, in the footprint of a single sofa. If you've been asking what is a sofa bed and how to pick the right one, this guide walks you through it in six clear steps.

What Is a Sofa Bed?

The defining feature is the mechanism. Every sofa bed is built around one — hidden inside the frame, or integrated into the cushions themselves — and it's what lets you switch between seating and sleeping in anything from a few seconds to a couple of minutes.

Sofa beds earn their place in flats, studios, home offices and living rooms that occasionally double as a spare room. If you want to see what's available before reading on, browse the Koala sofa bed collection.

What qualifies as a sofa bed? Three things: it works as everyday seating, it converts to a flat sleeping surface without dismantling anything, and it has a dedicated sleep surface — a mattress, a mattress-grade topper, or a seat designed to double as one. A sofa you can nap on isn't a sofa bed. A daybed isn't either: it's a bed styled as seating, and it doesn't convert.

UK vs US sofa bed terminology

In the UK, the standard term is sofa bed (you'll also see sofa-bed, sofabed and, more traditionally, bed settee). The American terms turn up constantly on furniture sites and in hotel listings, so here's the translation:

One distinction matters in the UK: a futon here means a wooden or metal slatted frame with a separate fold-flat cotton or foam mattress — the Japanese-derived design sold by specialists. Americans use "futon" for what we'd call a clic-clac. If you're weighing the two, we've compared them in futon vs sofa bed.

How Does a Sofa Bed Work? Types and Mechanisms

Every sofa bed does the same job, but the mechanism is what sets each type apart. It determines how fast the bed converts, how much floor space it needs, and how comfortable it feels once it's open.

The classic pull-out sofa bed hides a folded mattress inside the frame. You lift off the seat cushions and pull the frame forward until it unfolds. A good one sleeps close to a real bed — but the folding forces the mattress to be thin, and cheaper models are notorious for the metal support bar you can feel through it. If that's your worry, we've rounded up the bar-free options.

Within pull-outs, there's a distinction worth knowing: two-fold frames are sturdier and can carry a thicker mattress, while three-fold frames pack down smaller but force a thinner one. If you're replacing a sofa bed mattress later, you have to match the fold count — a three-fold mattress won't sit properly on a two-fold frame.

A clic-clac (also spelled click-clack, and sometimes klik-klak) works on a ratchet. Push the seat down, and the backrest clicks through three positions: upright, lounging, flat. Conversion takes seconds rather than minutes, and there's no frame to wrestle with, which is why it dominates the budget end of the market. The catch is that you sleep directly on the seat cushions, so comfort depends entirely on how good those cushions are, and the join between seat and back sits right under your hips. Full detail in our clic-clac sofa bed guide.

The Italian or pull-forward mechanism rolls the whole frame forward on wheels with the mattress already flat, so the mattress never folds. No fold lines, no bar, and it needs slightly less clearance than a traditional pull-out. It's usually found at the premium end of the market.

Flip-style designs skip the separate folding mattress entirely. The seat cushions flip back to uncover a full-length integrated mattress, so there's no metal frame to lift. The Koala Sofa Bed [4th Gen] uses this FlipBed™ approach with a Kloudcell™ topper — an open-cell foam that balances the contouring feel of memory foam with more airflow.

Sofa Bed Sizes UK

Mechanism sorted, the next question is how much bed you actually get — and this is where sofa beds get slippery.

Here's the thing most size guides skip: a sofa bed's sleeping surface rarely matches a standard UK bed size. Standard UK mattresses are 190 cm or 200 cm long, but sofa bed mattresses across the high street are commonly 180–183 cm, because the mechanism has to fold into the sofa's depth. Check the actual sleeping dimensions in centimetres, not the size label.

Standard UK bed sizes for reference:

Two traps worth naming. First, the seater count is not the bed size — "2-seater sofa bed" tells you about the sofa, not the mattress, and the sleeping width of a "double" sofa bed can vary by 30 cm or more between brands. Second, standard bedding often won't fit. A fitted sheet cut for the size on the label will ruck on a mattress that's shorter than it. Check the sleeping length before you buy the bedding.

The Koala Sofa Bed [4th Gen] is a useful counter-example, because it runs the other way. All three sizes sleep 209 cm long — longer than a standard UK bed at 190 cm, and longer than a UK King at 200 cm:

That 209 cm length is worth knowing if anyone in the house is over six foot — it's the dimension most sofa beds sacrifice first.

Working with a smaller room? The space-saving sofa beds collection filters to what fits, and we've written up single sofa beds and compact options under 200 cm separately.

How to Choose a Sofa Bed in 6 Steps

With the types and the sizing straight, the buying decision itself becomes a sequence. Choosing a sofa bed comes down to six steps: measure the space closed and open, decide how often it'll be slept on, pick a mattress type and depth, check the mechanism, verify the warranty and returns terms, and test the seating comfort. Work through them in order, and you'll avoid the most common — and most expensive — buying mistakes.

1. Measure the space closed, open, and on the way in

Measure the sofa closed and fully open, because most people forget the second part. A pull-out extends a long way forward: allow around 2 metres of clear floor in front of a traditional pull-out, and at least 30 cm beyond the foot of the bed so you can actually operate it. For scale, every size of the Koala Sofa Bed needs 222.5 cm of total depth in bed mode against 104.5 cm closed — more than double its closed footprint, and the same whichever width you pick.

Then measure the route in, which is where most delivery failures happen. A standard internal door leaf in England and Wales is 762 mm wide, but that isn't the gap you get: once the frame, stop and hinges are accounted for, the clear opening is closer to 700 mm, and narrower again in Scotland. Measure the actual gap, not the door — along with the tightest corner, the stairwell turn and any low ceiling on the way. Flat-packed sofa beds sidestep this almost entirely; the Koala ships in five boxes, the largest 162 × 40 × 40 cm on the 3-Seater and smaller on the other two sizes, which is why it works for renters and upstairs flats.

The tape trick: mark the open dimensions on your floor with masking tape or newspaper before you order, then live with it for a day. Walk the route you'd actually walk. It catches problems no spreadsheet will.

More on this in our guide to sofa beds for narrow rooms.

2. Decide how often it'll be slept on

Be honest about the use case, because it drives every other choice.

• A few nights a year — a simple mechanism and a basic sleep surface will do.

• Monthly or more — step up on both mattress depth and frame strength.

• Most nights — treat it as a bed that happens to be a sofa. Prioritise an integrated mattress, a reinforced frame and a mechanism rated for daily use.

Frame quality matters more here than on a normal sofa, because the frame carries the mechanism's weight as well as yours. Softwood that would be fine under a standard three-seater can flex under a pull-out. Look for hardwood or engineered ply — the Koala frame uses FSC®-certified poplar plywood and MDF.

If it's mainly for visitors, the sofa beds for overnight guests collection is the place to start. If it's going to be slept on regularly, see sofa beds for daily sleeping; if two adults will share it, sofa beds for couples.

3. Pick a mattress type and depth

The sleep surface is the single biggest factor in how comfortable a sofa bed feels, and depth is the number to check first.

Depth guidance used across the UK market:

• Under 10 cm — below the sensible minimum. It will feel exactly as thin as it is.

• 10–12 cm — the high-street norm, and the floor for occasional guests. Fine for a few nights.

• 12–15 cm — comfortable for regular guests.

• 15 cm+ — approaching proper-bed territory; usually only on integrated or Italian-mechanism designs.

The five types you'll be offered:

Integrated systems change the calculation, because there's no fold and no frame to design around. The Koala Sofa Bed uses a full-length mattress with a Kloudcell™ open-cell foam topper, plus Zero Disturbance™ — a construction that absorbs movement so one person turning over doesn't wake the other. With an integrated surface, foam quality matters more than raw depth. Full breakdown in our sofa bed mattress guide.

4. Check the mechanism

A sofa bed that's a chore to open ends up never being opened. Roughly: a clic-clac or a flip system converts in seconds; a traditional pull-out takes noticeably longer and involves some lifting. If you'll be setting up guest space often, or if whoever makes the bed can't lift a heavy frame, faster and lighter wins.

Two things to test if you can: open and close it several times, because a stiff mechanism only gets stiffer; and check whether it needs tools. The Koala Sofa Bed is entirely tool-free — no Allen keys, no screwdrivers, everything slots or zips with coloured alignment guides.

5. Verify the warranty, trial and your legal rights

Warranty length signals how long a maker expects the frame and mechanism to last. Check what's actually covered — some makers warrant frame, mechanism and foam for different periods — and what a return would cost you. Collection fees are the hidden expense here, ranging at the time of writing from about £25 to over £100 across UK retailers.

Your statutory rights in the UK, separate from any retailer policy:

• Consumer Contracts Regulations 2013 — buying online gives you a minimum 14-day cooling-off period from the day after delivery, no reason needed, with the refund due within 14 days.

• One important exception: goods made to your specification — a bespoke fabric, a made-to-order configuration — are exempt from the right to cancel, provided the retailer told you clearly before you bought. Most premium UK sofa makers build to order, so check this before you assume you can change your mind.

• Consumer Rights Act 2015 — a separate 30-day right to reject anything faulty, on top of the above.

Retailer policies are usually more generous than the statutory floor. Koala sofa beds come with a 5-year limited warranty (excluding Northern Ireland) and a 120-day trial — if it isn't right, Koala collects it free and refunds you in full, including delivery, even if you've used it.

6. Test the seating comfort

You'll sit on it far more than you sleep on it, so don't judge it on bed mode alone. Sofa beds are often shallower than standard sofas because the mechanism eats into the depth. As a rule of thumb, under 50 cm of seat depth tends to feel perched, and 55–60 cm suits most people. The Koala Sofa Bed runs a 63 cm seat depth with a 46 cm seat height.

Check cushion density too — press down hard and see how fast it recovers. And sit with your feet flat on the floor for a few minutes, not just perched on the edge. If you're buying online, an at-home trial is the only real substitute for a showroom.

Are Sofa Beds Comfortable?

All six steps circle the same underlying question, so it's worth answering it directly. Sofa beds can be very comfortable, but the range is enormous. A well-built sofa bed with a deep, high-density mattress and no metal bar underneath will sleep close to a spare bed. A budget clic-clac with 8 cm of foam over a hard join will not, and no amount of styling changes that.

What are the disadvantages of a sofa bed?

Every sofa bed is a compromise. The useful question is which compromise you can live with:

• The mattress is thinner than a real one. Physics: it has to fold into a sofa. Integrated and Italian designs get around this; folding designs mostly can't.

• It's often shorter than a standard bed. Many are 180–183 cm against a UK standard 190 cm. Fine at 5'6", not at 6'2".

• The seat can be shallower, because the mechanism takes up depth.

• Nightly use wears it faster than a bed or a sofa used for one job.

• Hygiene is harder. You sit on it in outdoor clothes all day, then sleep on it, and you can't strip and wash it the way you would a bed. Worth thinking about if anyone in the house has allergies.

• You need somewhere to keep the bedding. Sofa beds with storage or a separate ottoman solve this; otherwise it lives in a cupboard.

• It costs more than the equivalent sofa without a bed in it — typically 30–50% more.

None of that makes a sofa bed the wrong buy. It makes the specification the thing that matters.

Can you sleep on a sofa bed every night?

Yes, with the right one. For occasional guests, most decent sofa beds are more than good enough. For nightly use, the model matters far more than the category: look for an integrated or unfolded mattress at the deeper end of the range in Step 3, a reinforced frame, and no pressure points underneath.

Sleep-focused brands have closed most of the gap with a standalone bed, though a dedicated mattress will still go further for anyone who needs a specific level of long-term support. A thin budget model won't cope — it'll sag within months, and it isn't built for the load.

How to make a sofa bed more comfortable

Four fixes, in order of impact:

1. Add a mattress topper. A 5–7 cm memory foam or gel-infused topper is the single biggest improvement, and it bridges any fold line or bar.

2. Use proper bedding, not a spare duvet folded double — a fitted sheet sized to the actual mattress, a real duvet and proper pillows.

3. Check the surface underneath. If you can feel the support bar, a bed board or a bar shield — a rigid panel that sits between the mattress and the frame — costs very little and removes the ridge.

4. Sort the room. Blackout blind, cool temperature, somewhere to put a phone and a glass of water.

If everyday comfort is the priority from the start, see the most comfortable sofa beds for daily use.

How Much Should a Sofa Bed Cost in the UK?

Frame, mattress, mechanism: every one of those costs money to get right, which is why price in this category tracks specification more closely than it tracks brand. Roughly, the UK market breaks into four bands.

A useful rule of thumb: a sofa bed tends to cost 30–50% more than the equivalent sofa without a bed inside it. If it doesn't, the saving has usually come out of the mattress or the frame. Our guide to sofa beds under £1,500 covers what to look for and what to skip in the busiest band.

Find Your Koala Sofa Bed

Run those six steps, and you end up with a shortlist defined by mechanism, mattress depth, frame and returns terms. Here's how Koala's UK range answers each.

The range is deliberately short: one sofa bed in three sizes, plus a matching ottoman. All three sizes convert tool-free, ship free to England, Scotland and Wales (some postcode exclusions apply), and come with a 120-day trial and a 5-year limited warranty.

All three share a 63 cm seat depth, a 46 cm seat height, a 58 cm arm height and a 222.5 cm total depth in bed mode — so the open footprint is the same whichever size you choose. Only the width changes.

*Prices shown include the sign-up saving running at the time of writing, and premium fabrics cost around £100 more. Promotions change, so check the product page for live pricing.

The Koala Sofa Bed is designed in Sydney and built with sustainability in mind: FSC®-certified poplar plywood and MDF frames, PFAS-tested fabric treatments, and B Corp certification with a 1% for the Planet commitment.

A note on care, because it's commonly misunderstood — there are three different regimes:

• The sleep surface unzips and comes off for a cold machine wash. Don't bleach, soak, rub, or wring it.

• The outer covers are hand wash or dry clean — never machine wash.

• The linings have zips but aren't meant to come off at all. Spot clean only, and don't dry clean them.

Nothing goes in a tumble dryer or under an iron. Reshape everything while it's damp and line dry in the shade. Full instructions in our cover care guide.

Not sure which size? Compare all three on the Koala Sofa Bed product page, or see how they stack up in our best sofa beds of 2026 roundup. Need somewhere to keep the bedding? The Koala Sofa Bed Ottoman (£270) is a standalone storage piece that doubles as a footrest or side table — it sits alongside the sofa rather than attaching to it.

Frequently Asked Questions

What is the difference between a sofa bed and a sleeper sofa?

None in practice — "sleeper sofa" is the American term for what the UK calls a sofa bed. It usually implies the pull-out type with a mattress folded inside the frame. "Sofa bed" is the broader UK category and also covers clic-clacs, futons, Italian pull-forwards and integrated flip designs.

What type of sofa bed is the most comfortable?

Designs where the mattress doesn't fold: Italian pull-forward mechanisms and integrated flip systems both give you one continuous surface with no fold line and no support bar. Among folding designs, a two-fold pull-out with a pocket sprung or reflex foam mattress beats a three-fold, and both beat a clic-clac, where you're sleeping on the seat cushions.

What size sofa bed fits two people?

A double sleeping surface — roughly 135 × 190 cm — is the usual minimum for two adults; a king at 150 × 200 cm is more comfortable. Check the stated centimetres rather than the size label, and remember the seater count describes the sofa, not the bed.

How do I know a sofa bed will fit through my door?

Measure the narrowest doorway on the delivery route. A standard internal door leaf in England and Wales is 762 mm wide, but the clear opening is closer to 700 mm once the frame and hinges are accounted for, and narrower again in Scotland. Check the stairwell turn, the lift and any low ceiling too, and compare against the sofa's diagonal depth rather than its height, since it can be tilted on its side. Flat-packed sofa beds avoid the problem: the Koala arrives in five boxes and is assembled in the room.

What is a sofa bed in a hotel?

When a hotel listing says "sofa bed", it means a sofa in the room converts to an extra sleeping surface, usually a pull-out for one or two people. It's rarely equivalent to a proper bed, so if the room sleeps four "with sofa bed", two of those people are on a converted sofa. Worth checking before booking with children or a group.