Arthur Sleep Cool Pocket King Size Mattress
The Arthur Sleep Cool Pocket Mattress is a medium firm pocket spring mattress with 800 pocket springs and a gel foam comfort layer, which means you get targeted support with a top layer designed to draw heat away.
- Gel foam layer keeps you cooler
- Medium-firm feel suits most sleepers
- 60-night trial & 10-year guarantee
£255
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Arthur Sleep Cool Pocket Mattress
More available sizes
Mattress details
Mattress
Arthur Sleep Cool Pocket Mattress
Size
Firmness
Medium Firm
Construction
Foam
Pocket Spring
Depth (cm)
25
Layers
2
Layer Details
Gel foam comfort layer
A breathable gel foam layer that draws heat away from your body. In practice, this means a cooler sleeping surface than standard foam.
800 pocket spring support system
800 responsive pocket springs that move independently, giving targeted support where you need it. This also helps limit motion transfer if you share the bed.
Layer details from arthursleep.co.uk product page, September 2026.
Key benefits
- 75cm each for couples: Two people sharing get 75cm of width apiece, which means you can change position without negotiating for territory.
- Less partner disturbance: The 800 pocket springs respond individually, so one of you slipping out for an early shift transfers less movement across the bed.
- Extra length for taller sleepers: At 200cm, the UK king is 10cm longer than the UK double, a real difference if either of you is approaching six foot.
- Cooler for two: Two bodies generate more heat than one, and the breathable gel foam comfort layer draws warmth away from the surface.
- Manageable room demands: We suggest at least 2.7m x 2.9m for a UK king, which fits most main bedrooms without crowding out the wardrobes.
This size suits you if...
You share the bed every night and a UK double has started to feel like a squeeze, you or your partner wake each other with different schedules and want the pocket springs' motion isolation spread across a wider surface, or one of you is tall enough that the 200cm length matters as much as the width.
Consider another size if...
Your bedroom is smaller than the 2.7m x 2.9m we suggest for a UK king. The UK double would suit you better, needing at least 2.6m x 2.8m, though you'd give up 15cm of width and 10cm of length.
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FAQ's
Is the Arthur Sleep Cool Pocket Mattress in a UK king good for couples?
Yes, and it is the size we would point most couples towards. You get 75cm of width each, and the 800 pocket springs move independently, so a restless partner disturbs you less. The medium firm feel suits most sleepers, although a lightweight side sleeper sharing the bed may find it slightly firm.
Is the UK king long enough for someone over six foot?
At 200cm, the UK king is 10cm longer than the UK double, which is usually the difference between feet hanging off the end and lying flat comfortably. If one of you is notably tall, the extra length is arguably a bigger upgrade than the extra width.
Will a UK king Arthur Sleep Cool Pocket fit in my bedroom?
We suggest allowing at least 2.7m x 2.9m for a UK king, and that is our guidance rather than the brand's. New build master bedrooms can feel smaller than they look once wardrobes go in, so measure your usable floor space before committing. The mattress itself is 150 x 200cm, or 5ft x 6ft 6in.
Does the UK king version feel different from the smaller sizes?
The feel is the same across sizes: medium firm, 25cm deep, with the gel foam comfort layer over pocket springs. What changes is how you experience it as a couple. Across a wider surface, the independent springs have more room to isolate movement, so you feel less of your partner shifting about.
Should I choose the UK king or the UK super king?
The UK king is 30cm narrower than the UK super king, and both are the same length. If you allow a dog on the bed or simply want maximum space, the UK super king is tempting, but we suggest at least 3m x 2.9m of room for it. The UK king is the more practical fit for most bedrooms.