Silentnight Comfort Breathe 800 Super King Mattress
The Silentnight Comfort Breathe 800 is a medium-feel pocket sprung mattress built around 800 Mirapocket springs, which respond individually to your movements rather than moving as one block, so you get support where your body actually needs it.
- Cooler surface for hot sleepers
- Medium feel suits most sleepers
- 60-night trial & 5-year guarantee
£414.95
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Silentnight Comfort Breathe 800 Mattress
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Mattress details
Mattress
Silentnight Comfort Breathe 800 Mattress
Size
Firmness
Medium
Construction
Foam
Pocket Spring
Memory Foam
Depth (cm)
25
Layers
5
Layer Details
Sleep surface
A naturally hypoallergenic fabric that's soft and gentle on the skin. A reassuring choice if you're sensitive to allergens.
Comfort Breathe®
Silentnight describes these fibres as 15x more breathable than standard memory foam, promoting airflow and regulating temperature. In practice, that means a cooler surface for hot sleepers.
800 Mirapocket spring unit
800 individual pocket springs respond separately to your body's movements, which means zoned support and better spinal alignment. You shouldn't roll towards a partner every time they turn over.
Protective Layer
This layer disperses pressure from the spring unit across the mattress. It's there to help the mattress last longer.
Durable case
A soft, hard-wearing case designed to keep the mattress comfortable for years to come.
Layer details from silentnight.co.uk product page, September 2026.
Key benefits
- 90cm each for two sharing: That's 90cm each for two people, so a restless partner turning over happens at a distance rather than against your back.
- Pocket springs across a wide bed: The 800 Mirapocket springs respond individually, which matters most at this width: movement on one side barely travels the 180cm to the other.
- Cooler sleeping for two: Two bodies under one duvet generate real heat, and the Comfort Breathe fibre layer is designed to move that warmth away rather than trap it.
- Room for the whole household: When children or a large dog treat your bed as theirs, the 6ft width means everyone still gets a usable share.
- An affordable route to maximum space: Super kings usually carry a serious premium, so a mattress from the affordable end of the market makes this size realistic for more budgets.
This size suits you if...
You share the bed every night and one of you is a genuinely restless sleeper, because at this width distance does more than any comfort layer can. Or your children or pets regularly join you and a smaller size leaves someone perched on the edge. You'll need the room for it: we suggest at least 3m x 2.9m, with around 3.5m x 3.2m feeling right.
Consider another size if...
Your bedroom falls short of the 3m x 2.9m we suggest, or you'd rather not pay super king bedding prices. The UK king would suit you better, and needs at least 2.7m x 2.9m by our guidance.
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FAQ's
Is the Silentnight Comfort Breathe 800 super king good for couples?
Yes, and arguably it's the size where this mattress makes most sense for two. You get 90cm each, and the 800 pocket springs move individually rather than as one block, so a partner turning over is far less noticeable across 180cm of width. The medium feel suits most sleepers, although fans of very firm or very soft surfaces should look elsewhere.
What room size do I need for the Comfort Breathe 800 in a super king?
We suggest at least 3m x 2.9m as a minimum, with around 3.5m x 3.2m feeling comfortable once you add bedside tables and space to walk around. These are our own recommendations, not Silentnight's. If your room is smaller, the UK king needs at least 2.7m x 2.9m by our guidance and may be the wiser buy.
How big is the Silentnight Comfort Breathe 800 super king?
It measures 180 x 200cm, which is 6ft x 6ft 6in. That makes it 30cm wider than the UK king and the same length, and the largest size UK retailers stock as standard. At 25cm deep, standard super king fitted sheets should go on without a struggle.
Is a super king worth it if children or pets share the bed?
Often, yes. This is the size where a child wandering in at night, or a large dog who considers the bed home, stops pushing an adult to the edge. The pocket sprung build helps too, since small bodies climbing in cause less ripple across the surface than an open coil would.
Does this mattress sleep hot at super king size?
No more than the smaller sizes, and there's a case it copes better. Two sleepers close together concentrate heat, whereas 180cm of width lets you spread out. The Comfort Breathe fibre layer, which Silentnight describes as 15x more breathable than standard memory foam, is designed to keep air moving through the sleep surface for both of you.