Dormeo Octasmart Premium Deluxe King Size Mattress
The Dormeo Octasmart Premium Deluxe is a memory foam hybrid with a Medium/Soft feel, available in UK Single, Double and King.
- Deeper, more cushioned surface
- Air system boosts breathability
- 200-night trial & 20-year guarantee
£479
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Dormeo Octasmart Premium Deluxe Mattress
More available sizes
Mattress details
Mattress
Dormeo Octasmart Premium Deluxe Mattress
Size
Firmness
Medium Soft
Construction
Foam
Memory Foam
Depth (cm)
Layers
2
Layer Details
Memory Foam Top Layer
A top layer of memory foam that moulds to your shape, which means the surface cradles your body rather than pushing back against it. Expect that slow, sinking-in feel memory foam is known for.
Octaspring Technology with Body Zones
Hundreds of Octasprings adapt three-dimensionally to ease pressure at the back, hips and shoulders, so support shifts as you move rather than staying rigid. Three Body Zones mean each area of your body gets a comfort point tuned to it.
Layer details from dormeo.co.uk product page, September 2026.
Key benefits
- 75cm each for two sharing: You each get 75cm of width, which means you can settle into the memory foam surface without negotiating elbow room all night.
- 15cm wider than the UK double: That 15cm over a UK double sounds modest on paper, but on a hugging Medium/Soft mattress it is the difference between cosy and cramped.
- 200cm of length for taller sleepers: At 200cm, the UK king is 10cm longer than the UK double, so a partner nudging six foot stops finding their feet at the edge.
- Room for real life: A dog who treats the bed as their own, or pillows propped everywhere during pregnancy, both fit far more comfortably at this width.
- Fits a normal master bedroom: We suggest a room of at least 2.7m x 2.9m, which most UK master bedrooms manage even once the wardrobes go in.
This size suits you if...
You share the bed every night and a UK double has started to feel tight, especially with a mattress this cushioned, where you sink in rather than perch. It also makes sense if one of you is on the tall side and wants the 200cm length, or if you keep different hours and want enough space that the early riser can slip out without a wrestle.
Consider another size if...
Your bedroom is smaller than the 2.7m x 2.9m we suggest for a UK king, or you sleep alone and the width would go unused. We'd recommend the UK double instead, which suits a room of at least 2.6m x 2.8m.
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FAQ's
Is the Dormeo Octasmart Premium Deluxe UK king big enough for two adults?
Yes, comfortably for most couples. At 150cm wide you get 75cm each for two people sharing, and because this mattress has a Medium/Soft feel that lets you sink in, that width helps each of you settle without drifting into the other's space. If you want still more room, Dormeo doesn't make this model in a super king.
What room size do I need for a UK king Dormeo Octasmart Premium Deluxe?
We suggest a room of at least 2.7m x 2.9m for a UK king, with around 3.2m x 3.2m feeling genuinely comfortable. New build master bedrooms often look bigger empty than they are once wardrobes and bedside tables go in, so measure the floor you'll actually have left before committing.
Is the UK king long enough for someone over six foot?
At 200cm, or 6ft 6in, the UK king gives a tall sleeper meaningful clearance. It is 10cm longer than the UK double, and for many taller people that length, rather than the width, is the real reason to size up. Anyone approaching six foot will notice the difference straight away.
How much bigger is the UK king than the double in this mattress?
The UK king is 15cm wider and 10cm longer than the UK double. Split between two people, that extra width works out at 75cm each for two sharing, and the added length takes the mattress to a full 200cm. On a Medium/Soft memory foam surface, that margin is easy to feel.
Where can I buy the Dormeo Octasmart Premium Deluxe in a UK king?
Compare the retailers listed on this page. The prices shown here are live and updated as retailers change them, so checking the table is more reliable than any figure we could print. It is worth confirming the size name at checkout too, since the UK king (150 x 200cm) differs from EU king dimensions.