Sealy PostureLux Forbes Super King Mattress
The Sealy PostureLux Forbes Mattress combines a latex comfort layer with PostureTech pocket springs and UniKey edge support, which means a buoyant, medium-feel surface with a stable edge to sit or sleep on.
- Buoyant latex pressure relief
- Springs adapt to your body shape
- Stable UniKey edge support
£2,199
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Sealy PostureLux Forbes Mattress
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Mattress details
Mattress
Sealy PostureLux Forbes Mattress
Size
Firmness
Medium
Construction
Foam
Latex
Pocket Spring
Depth (cm)
32
Layers
3
Layer Details
Latex comfort layer
A latex layer that delivers pressure relief and a naturally buoyant feel. You sit on the surface rather than sinking deep into it.
Sealy medium premium foam
A double layer of Sealy's medium premium foam, creating a complete comfort stack. It adds cushioning beneath the latex to keep the medium feel consistent.
PostureTech Core Support Plus springs
Springs with six turns each, twice tempered, with UniKey edge support. They adapt to your body shape and keep the edges steadier when you sit or sleep near them.
Layer details from crushedvelvetbedstore.co.uk product page, November 2026.
Key benefits
- A full 90cm each: Two adults sharing get 90cm apiece, the same width as a UK single each, so a restless partner's tossing happens well away from your side of the bed.
- 15cm more each than the UK king: The UK super king is 30cm wider than the UK king at the same length, which works out at 15cm more per sleeper when two of you share.
- Steadier edges for extra bodies: UniKey edge support helps the sides hold up, which matters when a child or dog ends up pushed towards the outer edge of the bed.
- Fills a big room properly: In a large master or a high-ceilinged period bedroom, a UK king can look a little lost, while 180cm of width sits in proportion with the room.
- Medium feel across the whole surface: The latex layer keeps you on top of the mattress rather than sinking in, so a small child sleeping in the middle won't roll into a dip.
This size suits you if...
You share with a partner whose fidgeting wakes you, or your children and pets regularly end up in bed with you, and your bedroom comfortably clears our suggested minimum of 3m x 2.9m.
Consider another size if...
Your bedroom is tighter than 3m x 2.9m, or you mostly sleep alone. We'd recommend the UK king instead, for which we suggest at least 2.7m x 2.9m.
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FAQ's
Is a Sealy PostureLux Forbes UK super king big enough for two adults and a child?
For a child who joins you some nights, yes. Two adults get 90cm each, so a small sleeper can fit between you without anyone clinging to the edge. If a child sleeps there every night, the UK super king is the most room this mattress offers, and the UniKey edge support helps when someone ends up near the side.
How much wider is the Sealy PostureLux Forbes super king than the king?
The UK super king is 30cm wider than the UK king, and both are the same length. For two people sharing, the UK king gives 75cm each and the UK super king gives 90cm each, so you each gain 15cm. That extra room is what keeps a restless partner's movement further from you.
What size bedroom do I need for a UK super king mattress?
We suggest at least 3m x 2.9m, with around 3.5m x 3.2m feeling more comfortable once you add bedside tables and space to walk round. In a loft conversion, measure where the ceiling is high enough to stand, because the slope often decides which wall the bed can go against.
What bedding fits a Sealy PostureLux Forbes UK super king?
You'll need UK super king sheets and a 260 x 220cm duvet. The mattress is 32cm deep, so check that any fitted sheet you buy has deep enough pockets to tuck under properly. Bedding at this size costs more than for a UK king, so budget for it alongside the mattress.
Will a UK super king mattress fit up my stairs?
Measure before you order. At 180cm wide and 32cm deep, a UK super king can catch on tight landing turns or a door that opens into the bedroom at an awkward angle. Check the narrowest point on the route, then compare the retailers listed on this page.