Rest Assured Kelbrook King Size Mattress
The Rest Assured Kelbrook is an extra firm pocket spring mattress built around 1400 pocket springs, which means each spring moves independently, so you get support that follows your shape rather than one solid push-back.
- Extra-firm for back & front sleepers
- Wool fillings help you stay cool
- Minimises partner disturbance
£656.10
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Rest Assured Kelbrook Mattress
More available sizes
Mattress details
Mattress
Rest Assured Kelbrook Mattress
Size
Firmness
Extra Firm
Construction
Pocket Spring
Depth (cm)
Layers
2
Layer Details
Pocket springs
A core of 1400 pocket springs, each sewn into its own fabric pocket so it compresses independently. In practice this means support that adjusts to where you place weight, and less motion transferring across the bed.
Wool fillings
Wool fillings sit above the spring unit, softening the surface slightly without undermining the extra firm feel. Wool also wicks moisture and breathes well, which helps if you tend to overheat at night.
Layer details from mattressman.co.uk product page, September 2026.
Key benefits
- More room each: At 75cm per sleeper, the UK king gives you 7.5cm more each than the UK double, which means less time spent negotiating over the middle of the bed.
- Length for taller sleepers: The UK king is 10cm longer than the UK double, so if one of you is over six foot, your feet are far less likely to reach the end.
- Calmer early starts: If one of you rises hours before the other, independent pocket springs plus the extra width keep that getting-up movement a little more contained on one side.
- Avoids the super king room demands: We suggest at least 2.7m x 2.9m for the UK king, against 3m x 2.9m for the UK super king, so it suits bedrooms where a UK super king would crowd the floor.
This size suits you if...
You share the bed every night and feel cramped on a UK double, one of you is tall enough that a shorter mattress leaves your feet near the edge, or your working hours differ and you'd like your partner's comings and goings to disturb you a little less.
Consider another size if...
Your bedroom is smaller than our suggested 2.7m x 2.9m, or you usually sleep alone. We'd recommend the UK double instead, which needs at least 2.6m x 2.8m.
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FAQ's
Is the Rest Assured Kelbrook UK king long enough for someone over six foot?
The UK king measures 150 x 200cm, or 5ft x 6ft 6in, which is 10cm longer than the UK double. If one of you is over six foot, that extra length is often the more useful part of the upgrade, giving your feet room rather than leaving them at the very end of the mattress.
How much space each do you get on a Kelbrook UK king?
Two people sharing get 75cm each. That's 7.5cm more each than the 67.5cm you'd have on the UK double. If you want more still, the UK super king gives 90cm each, though it needs a larger room.
Will I feel my partner moving on a UK king Kelbrook?
The 1400 pocket springs compress independently, so movement on one side travels less across the bed. In the UK king you also have more distance between you, which helps if one partner is up and out hours before the other. A very restless partner may still be noticeable, just less so.
Should I choose the Kelbrook in a UK king or a UK super king?
Both are the same length, so the choice is about width. The UK king gives 15cm less each than the UK super king. We suggest at least 2.7m x 2.9m for the UK king and 3m x 2.9m for the UK super king, so let your room size decide.
Will a Kelbrook UK king fit in a new build master bedroom?
We suggest at least 2.7m x 2.9m for the UK king. New build bedrooms can feel roomy when empty and shrink once fitted wardrobes go in, so measure the floor you'll actually have left. If you fall short, the UK double needs at least 2.6m x 2.8m.