Dormeo Octasmart Premium Plus King Size Mattress
The Dormeo Octasmart Premium Plus is a medium-feel mattress that pairs a memory foam top layer with Dormeo's patented Octasprings, honeycomb-shaped foam springs that flex in three dimensions rather than just compressing downwards, which means the surface adapts to your shape without the dead, sink-in feel some all-foam mattresses have.
- Foam springs adapt to your contours
- Spring-like feel without coil noise
- 200-night trial & 20-year guarantee
£419
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Dormeo Octasmart Premium Plus Mattress
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Mattress details
Mattress
Dormeo Octasmart Premium Plus Mattress
Size
Firmness
Medium
Construction
Foam
Pocket Spring
Memory Foam
Depth (cm)
Layers
2
Layer Details
Memory foam top layer
A pressure-relieving memory foam layer that moulds to your shape, cradling your body as you settle in. In practice this means less pressure on hips and shoulders, which side sleepers in particular tend to notice.
Octasprings
A layer of patented honeycomb-shaped Octasprings that move three-dimensionally, adapting to the contours of your body. Because they are made of foam rather than metal, you get spring-like responsiveness without the noise or firmness of a traditional coil.
Layer details from dormeo.co.uk product page, September 2026.
Key benefits
- Proper space for two: At 75cm each for two people sharing, you can both stretch out without keeping one elbow tucked in all night.
- Less partner disturbance: The foam Octasprings flex where you press rather than transferring movement across the bed, so an early alarm on one side is easier to sleep through.
- Length for taller sleepers: At 200cm long, anyone approaching six foot gets genuine clearance rather than toes brushing the footboard.
- Quiet by design: The Octasprings are foam rather than metal, which means no creak when one of you gets up hours before the other.
- A clear step up from a double: The UK king is 15cm wider and 10cm longer than the UK double, a difference you notice every night rather than only on paper.
This size suits you if...
You share the bed every night and a double has started to feel cramped, especially if one of you sleeps hot or fidgety and you both wake when the other moves. It also suits couples where one partner is approaching six foot, since the 200cm length is the real upgrade. If a dog has claimed a permanent spot at your feet, the extra room stops that becoming a nightly squeeze.
Consider another size if...
Your bedroom falls short of the 2.7m x 2.9m we suggest for a UK king, or you sleep alone. In either case we'd recommend the UK double instead, allowing at least 2.6m x 2.8m for it.
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FAQ's
Is the Dormeo Octasmart Premium Plus in a UK king big enough for a couple?
Yes, comfortably for most. At 150 x 200cm you get 75cm each for two people sharing, and the Octaspring layer flexes locally rather than tilting the whole surface, so you feel less of your partner's movement. Very restless sleepers wanting maximum separation would need a wider size, which Dormeo doesn't offer in this mattress.
What room size do I need for the Octasmart Premium Plus king?
We suggest a room of at least 2.7m x 2.9m for a UK king, with around 3.2m x 3.2m feeling comfortable once wardrobes and bedside tables are in. New build master bedrooms can be tighter than they first appear, so measure with your existing furniture in mind before committing to the 150cm width.
Is the UK king Octasmart Premium Plus long enough for tall sleepers?
At 200cm, or 6ft 6in, it gives useful clearance for anyone around the six foot mark, 10cm more than the UK double's 190cm. If one of you is tall, that extra length is often the reason to size up, more than the width. Genuinely very tall sleepers should still measure against their height plus pillow space.
Does the king size help if my partner gets up earlier than me?
It helps on two fronts. The width means their side of the bed is further from yours, and the Octasprings are foam rather than metal, so there's no coil noise as weight shifts. Across a 150cm surface, one person sitting up and leaving tends to register far less than it would on a double.
Where can I compare prices for the Octasmart Premium Plus in a king?
Use the price table on this page. The prices shown here are updated as retailers change them, so it's the reliable way to see what the UK king costs today rather than relying on a figure that may already be out of date. Check the size name carefully when you click through, as retailers list several sizes together.