Arthur Sleep Cool Memory Small Double Mattress
The Arthur Sleep Cool Memory Mattress is a hybrid with a medium firm feel, which means you get the contouring of foam with the support of springs underneath.
- Cooling gel foam for warm sleepers
- Suits back & combination sleepers
- Foam comfort over spring support
£309
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Arthur Sleep Cool Memory Mattress
More available sizes
Mattress details
Mattress
Arthur Sleep Cool Memory Mattress
Size
Firmness
Medium Firm
Construction
Pocket Spring
Hybrid
Memory Foam
Depth (cm)
Layers
4
Layer Details
Gel foam
A cooling, breathable gel foam that cradles you in a similar way to memory foam. It sits at the top, so it is the layer that manages heat first and gives the mattress its softer surface feel.
Memory foam
A memory foam layer that works with the gel foam above it to add support and comfort. It helps the surface ease around your body rather than pushing back against it.
Comfort foam
A high-resilience convoluted foam comfort layer, there for pressure relief. It adds a bit of bounce between the softer foams and the springs below.
800 pocket springs
Individually fabric-wrapped pocket springs that give targeted support and help isolate motion. Because each spring works on its own, you should notice less of a partner's movement across the bed.
Layer details from arthursleep.co.uk and mattressman.co.uk product pages, October 2026.
Key benefits
- Real room for one: At 30cm wider than the UK single, this size lets a solo sleeper roll and sprawl without an elbow hanging off the edge.
- Fits compact bedrooms: Being 15cm narrower than the UK double, it can be the difference between a door that clears and one that doesn't in a box room or studio.
- Cooling where you actually lie: The gel foam layer draws heat away across the full 120cm width, useful for a solo sleeper who tends to migrate around the bed.
- Medium firm across the middle: Solo sleepers get the supportive centre of the mattress every night rather than a worn edge, which suits back and combination sleeping positions.
- Sensible for guest rooms: Couples can share 120cm for the occasional night, so it works in a spare room or holiday let where nobody sleeps two-up nightly.
This size suits you if...
You sleep alone and have outgrown a single but your room can't take a 4ft 6in frame, you're furnishing a loft conversion or box room where every centimetre of floor matters, or you need a guest bed that occasional couples can share without dominating a small second bedroom.
Consider another size if...
You share the bed most nights, as 120cm gets tight quickly for two. We'd recommend the UK double instead, which is 15cm wider and the same length; allow a room of at least 2.6m x 2.8m for it.
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FAQ's
Is a small double big enough for one adult on the Arthur Sleep Cool Memory Mattress?
Comfortably, yes. At 120 x 190cm you get 30cm more width than a UK single, which is enough to change position freely without edging off the mattress. The medium firm feel means you're supported wherever you settle, and the cooling gel layer covers the whole surface, so a restless sleeper still gets the temperature benefit.
Can a couple share the Arthur Sleep Cool Memory small double?
For the odd night, yes, which makes it a reasonable guest room choice. For every night, 120cm is a squeeze: two adults will feel each other's movement despite the foam layer's contouring. If someone will share it regularly, we'd point you to the UK double, which is 15cm wider at 135 x 190cm.
What room size do I need for the small double version?
We suggest at least 2.4m x 2.8m for a UK small double. That allows walking space around the frame rather than the mattress alone, so check your own layout, particularly where the door swings. In a loft conversion, also think about where the ceiling height allows you to stand beside the bed.
How much smaller is the small double than the UK king?
The UK small double is 30cm narrower than the UK king and 10cm shorter, so the difference is substantial in both directions. The small double is 120 x 190cm against the king's 150 x 200cm. If your room measures at least 2.7m x 2.9m and you share nightly, the UK king is the better long-term buy.
Where can I buy the small double Arthur Sleep Cool Memory Mattress?
Availability for this size changes, so the most reliable answer is the retailer table on this page, where prices are updated as retailers change them. Arthur Sleep publishes little detail beyond the basics of this mattress, so if a spec matters to you, check the listing itself before ordering, as the 4ft size shares the same construction as the others.