Silentnight 800 Mirapocket Mattress
Mattress
Silentnight 800 Mirapocket Mattress
Size
Firmness
Medium Firm
Construction
Depth (cm)
26
Layers
2
Layer Details
- Eco Comfort Fibre. A comfort layer made from sustainable materials including repurposed plastic. It's highly breathable, which means air circulates freely through the mattress for a fresher, cooler feel through the night.
- Mirapocket Springs. 800 individual pocket springs, zoned to give targeted relief to your back, joints and hips. Because each spring moves independently, the mattress responds to your body shape and absorbs movement, so a restless partner is less likely to wake you.
Layer details from mattressonline.co.uk product page, September 2026.
- 75cm each for two sharing: That is your own single-bed's worth of width, so you can stretch out without negotiating territory in the small hours.
- Pocket springs plus distance: The 800 individual springs absorb movement on their own, and the UK king's extra width means less of your partner's tossing reaches you at all.
- Room for early risers: If one of you leaves for work hours before the other, the combination of independent springs and personal space makes the quiet exit far less disruptive.
- 200cm of length: The UK king is 10cm longer than the UK double, a genuine relief for anyone approaching six foot whose feet currently meet the end of the bed.
- Breathable across a bigger surface: The Eco Comfort Fibre layer lets air move through the mattress, and with more mattress between you, shared body heat is easier to escape.
This size suits you if...
You share the bed every night and the UK double has started to feel like a compromise, with one of you sleeping along the edge. Or one of you is over six foot and it is length you are really shopping for, since the UK king runs to 200cm. It also suits couples on different schedules, or anyone whose dog has quietly claimed a share of the bed.
Consider another size if...
Your bedroom falls short of the 2.7m x 2.9m we suggest for a UK king. In that case we'd recommend the UK double instead, which needs at least 2.6m x 2.8m and still gives couples a proper shared bed.
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Is the Silentnight 800 Mirapocket king big enough for a couple?
For most couples, yes. At 150cm wide you get 75cm each for two people sharing, and the 800 pocket springs respond to each sleeper separately, so a restless partner disturbs you less. Lightweight side sleepers should still note the medium firm feel, which some owners found firmer than expected, but the space itself is generous.
How much bigger is a UK king than a double in this mattress?
The UK king is 15cm wider and 10cm longer than the UK double, taking you to 150 x 200cm. The width is what you notice night to night, while the extra length is the difference for anyone approaching six foot. The build itself, springs, depth and feel, is identical across both sizes.
What room size do I need for the Silentnight 800 Mirapocket in a UK king?
We suggest a room of at least 2.7m x 2.9m for a UK king, which leaves walking space around the bed. Measure with wardrobes and drawers in place rather than off the floor plan; a new build master bedroom can feel much tighter once the furniture is in.
Is the UK king long enough for someone over six foot?
At 200cm, or 6ft 6in, it gives a taller sleeper meaningful clearance and is 10cm longer than the UK double. If length is your priority, sizing up further to the UK super king adds nothing here: it is 30cm wider but exactly the same length as the UK king.
Where can I still buy the 800 Mirapocket in a UK king?
This mattress is listed as discontinued at Mattress Online, so stock in any size can be patchy. Compare the retailers listed on this page; the prices shown here are updated as retailers change them. If the UK king shows as available, it may be remaining stock, so it is sensible to move reasonably quickly.