Arthur Sleep King Arthur Super King Mattress
The King Arthur from Arthur Sleep is a pocket spring mattress in a medium firm tension, which means springs that respond to your body individually rather than as one block, with a supportive rather than sink-in feel.
- Medium-firm for side & back sleepers
- Minimises partner disturbance
- Support follows your body's shape
£665
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Arthur Sleep King Arthur Mattress
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Mattress details
Mattress
Arthur Sleep King Arthur Mattress
Size
Firmness
Medium Firm
Construction
Pocket Spring
Depth (cm)
Layers
3
Layer Details
Memory foam comfort layer
A 20mm layer of memory foam sits in the comfort layer, as specified by the brand. It adds a little cushioning over the springs beneath, so the surface has some give without feeling like a deep foam hug.
Mini pocket springs
An additional layer of 1200 mini springs sits within the top of the mattress. Smaller springs can respond more closely to your body's shape, so they add finer contouring over the main spring unit below.
Base pocket springs
800 pocket springs form the base of the mattress. Each spring moves independently, which gives the underlying support and helps limit how much you feel a partner moving.
Layer details from mattressman.co.uk and arthursleep.co.uk product pages, October 2026.
Key benefits
- 90cm each for two sharing: Two people sharing get 90cm each, which means a partner's fidgeting happens far enough away to sleep through.
- Pocket springs plus distance: Each spring responds individually, so movement transfers less to begin with, and the extra width means what does transfer rarely reaches you.
- Space when the family piles in: A child wandering in at 3am, or a large dog treating the bed as routine, no longer means someone clinging to the edge.
- 30cm wider than a UK king: The UK super king is 30cm wider than the UK king at the same length, a difference you feel every night rather than a spec-sheet detail.
- Medium firm across a wide surface: The supportive, non-sink-in feel holds consistent across the full 180cm, so neither sleeper drifts into a dip in the middle.
This size suits you if...
You share the bed every night and want the most sleeping space a standard UK size offers, your partner turns frequently and you've decided distance is the fix, or children or pets regularly join you and everyone still needs their own share. It also suits a large master or period bedroom where a UK king would look a little lost against the wall.
Consider another size if...
Your bedroom falls short of the 3m x 2.9m we suggest as a minimum, or you'd rather spend less on bedding and sheets. We'd recommend the UK king instead, which is 30cm narrower at the same length and needs at least 2.7m x 2.9m.
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FAQ's
Should I buy the King Arthur in a UK king or a UK super king?
If you share every night and the room allows it, the UK super king. It's 30cm wider than the UK king at the same length, which is the difference between sensing a partner turn and barely noticing. Solo sleepers, or couples with a room under 3m x 2.9m, will find the UK king the more sensible fit.
How much space does each person get on a super king King Arthur?
Two people sharing get 90cm each, the same width as a UK single apiece. Combined with pocket springs that compress individually rather than as one block, that gap means a restless partner's movement mostly stays on their side. It's the main reason couples size up to a UK super king.
Is the King Arthur super king big enough to share with children or pets?
Yes, and this is where the size makes sense. At 180cm wide there's room for a child who appears in the night, or a large dog with settled habits, without either adult being pushed to the edge. On a UK double or UK king the same visitors usually cost someone their sleep.
Will the King Arthur in a super king fit through my house?
Measure before you order. At 180 x 200cm this is the size where door swings, tight landing turns and narrow loft stairs start to bite, and a sprung mattress can't be folded the way foam sometimes can. Check the awkward points of the route, particularly in older properties, before committing.
What size room do I need for the super king version?
We suggest at least 3m x 2.9m, with something nearer 3.5m x 3.2m feeling comfortable once you add bedside tables on both sides and space to walk around. If your room is smaller, the UK king needs at least 2.7m x 2.9m and gives up 30cm of width, nothing in length.