What Size Sofa Bed Do I Need?
Wondering what size is a sofa bed? The answer depends on the style and seating capacity. From compact single sofa beds to spacious corner models, sizes can vary considerably. In this guide, we'll cover the most common sofa bed dimensions, how to measure them and how to choose the right size for your space.
How big is a sofa bed?
Sofa beds come in all sorts of sizes, from single chair beds to six-seater corner models, so there's no single answer. Most fold down to somewhere between 150cm and 300cm wide. The most common size on the market is the double sofa bed, usually a 2 or 3-seater that opens out to a double-sized bed, roomy enough for two adults and compact enough for a typical living room.
Read our full sofa beds buying guide for more information on sizes, styles and types.
How do sofa bed measurements work?
Sofa bed sizes are described in two ways: how many people they seat as a sofa (2-seater, 3-seater, 4-seater) and how big the mattress is once opened out (single, double, king). The sofa bed width and depth are measured with the bed folded away, while the sleeping area is measured separately, once it's extended. Always check both figures, since seat count doesn't always match bed size.
What sizes do sofa beds come in?
From compact singles to family-sized corner beds, here's how each size compares.
Single sofa beds
Single sofa beds are the smallest option, usually folding down to around 80-100cm wide. They seat one person comfortably and sleep one adult, with a sleeping surface close to a standard single mattress at roughly 90 x 190cm. They're a smart choice for a home office, box room or anywhere space is at a premium.
Double sofa beds
A standard double sofa bed folds down to around 150-180cm wide and seats two people. Extended, they open into a double bed that sleeps two people, roughly 135-140cm wide, with a length of around 190cm.
3-seater sofa beds
A 3-seater sofa bed folds down to around 190-230cm wide, giving generous everyday seating for three. Most open out to a double or king-sized bed, roughly 140-150cm wide by 190-200cm long, so two adults can sleep without feeling cramped. It's a popular choice for households that use the bed function regularly, not just for occasional guests.
4-seater sofa beds
4-seater sofa beds are wider still, typically 230-260cm when folded, and suit larger living rooms that need to seat the whole family. Despite the extra seating, most still open out to a double or king-sized bed, around 140-160cm wide by 190-200cm long, since there's a limit to how wide a mattress can comfortably sit within the frame.
6-seater sofa beds
6-seater sofa beds are among the largest in the range, often modular or corner-shaped, folding down to 280cm or more. They seat up to six people for everyday lounging, while the sleeping area usually still tops out around a double or king-size, roughly 150-160cm wide by 200cm long, since only one section of the sofa converts into the bed.
Corner sofa beds
Corner sofa beds are L-shaped, typically measuring 220-300cm along the longest side, and seat 4 to 6 people thanks to the extra chaise section. They usually sleep 2 adults on a double or king-sized mattress, around 140-160cm wide by 190-200cm long, and many come with handy storage underneath the chaise for spare bedding. Read our corner sofa bed buying guide for more information.
Sofa bed dimensions
Here's how each size compares side by side, so you can see seating and sleeping capacity at a glance.
| Sofa bed size | Folded width | Seats (as a sofa) | Sleeping surface | Sleeps |
|---|---|---|---|---|
| Single | 80-100cm | 1 | 90 x 190cm | 1 adult |
| Double | 150-180cm | 2 | 135-140 x 190cm | 2 adults |
| 3-seater | 190-230cm | 3 | 140-150 x 190-200cm | 2 adults |
| 4-seater | 230-260cm | 4 | 140-160 x 190-200cm | 2 adults |
| 6-seater | 280cm+ | 6 | 150-160 x 190-200cm | 2-3 adults |
| Corner | 220-300cm | 4-6 | 140-160 x 190-200cm | 2 adults |
Figures are typical ranges and vary by model and mechanism, so always check the exact spec on the product page before you buy.
What size is a sofa bed mattress?
Sofa bed mattresses tend to be shallower than a normal bed mattress, usually around 10-14cm deep rather than the 20-25cm you'd find on a proper bed. Width follows regular UK bed sizing (single, small double, double or king), but sofa bed length is often a little shorter than a full-size bed, typically 180-200cm. It's worth checking the exact mattress dimensions before assuming they'll match your existing bedding.
What size sheets fit a sofa bed?
Because sofa bed mattresses are thinner, a standard fitted sheet in the matching size (single, double or king) will usually fit, just with a little extra fabric to tuck in. Match the sheet to the sleeping width and length rather than the sofa's seat count, and go for a shallow-fitting sheet if the mattress is on the slim side.
How to measure for a sofa bed
Sofa bed diagrams can look like a lot at once, so focus on the essentials. Measure the sofa bed width and depth while it's folded away, to check it fits your room and doorways. Then measure the sleeping area separately, including the mattress width and the length of sofa bed when open. Leave at least 50-60cm of clearance at the foot of the bed for walking round it.
How to choose a sofa bed size
Once you know the numbers, choosing the right size comes down to a few practical considerations.
- Room size: Measure your room in its everyday layout and with the bed fully extended, since the sofa bed length when extended often takes up more floor space than people expect.
- How often it'll be used as a bed: Occasional guests can manage with a smaller single or double, but a sofa bed used weekly deserves a proper double or king-sized mattress for lasting comfort.
- Number of sleepers: One adult is comfortable on a single, two need at least a double, and larger households hosting regularly should look at 4-seater or corner options.
- Mechanism type: Pull-out, click-clack and corner designs all need different amounts of space to open, so check the mechanism alongside the size.
- Storage needs: If you're short on cupboard space, a sofa bed with storage can tuck spare bedding away neatly underneath, ready for the next guest.
- Access and doorways: A generously sized sofa bed is no good if it won't get through the front door, so measure hallways, stairs and doorways before you order.
Whatever size you choose, our full range of sofa beds covers everything from compact singles to full corner beds with built-in storage. Still not sure which will fit your room? Our sofa measuring guide walks through it step by step, or give our team a call; we're always happy to help.
