Arthur Sleep Cool Memory King Size 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
£359
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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
- Space to sleep on different schedules: With 75cm each for two people sharing, an early alarm on one side is less likely to travel across the bed and wake the other.
- Length for taller sleepers: At 200cm long, this UK king adds 10cm over the UK double, so a partner over six foot stops waking with their feet at the edge.
- Cooling shared between two: Two people sharing generate more heat than one, and the gel foam layer is designed to draw that warmth away rather than trap it.
- Springs steady the extra width: The hybrid build puts springs under the foam across the full 150cm, which means support stays consistent whether you sleep centrally or right at your own edge.
- Room for the dog too: If a pet claims the foot of the bed most nights, the UK king absorbs that lost space in a way the UK double never quite does.
This size suits you if...
You share the bed every night and have started to feel the UK double's limits, one of you is up before dawn while the other sleeps on, or a partner near or over six foot keeps running out of length. Allow at least 2.7m x 2.9m of bedroom, though 3.2m x 3.2m is more comfortable once wardrobes go in.
Consider another size if...
Your room falls short of the 2.7m x 2.9m we suggest for a UK king, as is common in a new build master once furniture is placed. The UK double would suit you better; allow at least 2.6m x 2.8m for it.
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FAQ's
Is a UK king big enough for a couple with a restless sleeper?
For most couples, yes. At 150cm wide it gives 75cm each for two people sharing, and the hybrid construction, foam over springs, keeps movement fairly localised. If one of you tosses a great deal, or a dog joins you most nights, the UK super king adds another 30cm of width.
Will the Arthur Sleep Cool Memory in a UK king suit a tall sleeper?
The UK king is 200cm long, which is 10cm longer than the UK single, small double and double. For anyone approaching or past six foot, that length is often the real reason to upgrade, more than the width. In imperial terms it's 5ft x 6ft 6in.
How much wider is the UK king than the double for this mattress?
The UK king is 15cm wider than the UK double, and 10cm longer too. Spread between two sleepers, that width is the difference between negotiating space and simply having your own. If you're upgrading mainly to reduce disturbance from a partner, it's the change you'll feel most.
What room size do I need for this mattress in a UK king?
We suggest at least 2.7m x 2.9m, with 3.2m x 3.2m feeling comfortable. That's our guidance, not the manufacturer's, and it assumes space to walk both sides and open drawers. Newer build master bedrooms can look bigger than they measure, so check with a tape before ordering.
Where can I buy the Arthur Sleep Cool Memory Mattress in a UK king?
Compare the retailers listed on this page; the prices shown here are updated as retailers change them. Availability at this size can shift, so it's worth checking back if you're not ready to buy today. Arthur Sleep publishes little detail beyond the basics, so the listing itself may be brief.