Silentnight 3 Zone Memory Foam King Size Mattress
The Silentnight 3 Zone Memory Foam Mattress is a firm memory foam mattress with an 18cm depth.
- Firm feel for back & front sleepers
- Eases pressure at hips & shoulders
- Fits UK & EU bed frames
£319
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Silentnight 3 Zone Memory Foam Mattress
More available sizes
Mattress details
Mattress
Silentnight 3 Zone Memory Foam Mattress
Size
Firmness
Firm
Construction
Foam
Rolled
Memory Foam
Depth (cm)
18
Layers
2
Layer Details
Soft Knitted Sleep Surface
A soft, breathable knitted cover that adds a touch of comfort at the surface. It takes a little of the edge off the firm feel beneath.
Memory Foam
Body-moulding memory foam that responds to your shape, which means pressure points at the hips and shoulders get some relief. Expect a contouring, cradled feel rather than bounce.
Layer details from mattressnextday.co.uk product page, September 2026.
Key benefits
- Genuine space for two: At 75cm each for two people sharing, you can both change position without negotiating for territory, which matters most on a firm mattress where you settle where you land.
- Movement stays on one side: Memory foam soaks up motion rather than transmitting it, so in a UK king a partner leaving hours before you is far less likely to wake you.
- Extra length for taller sleepers: The UK king is 10cm longer than the UK Double at 200cm, welcome relief if one of you is approaching six foot and used to feet hanging over the edge.
- Firm support across the full width: The solid, body-moulding feel holds up right across 150cm, useful for back and front sleepers who tend to sink too far into softer foams.
- Budget-friendly at the popular size: King is where many mattresses get expensive, and this one stays at the affordable end; compare the retailers listed on this page for the current price.
This size suits you if...
You share the bed every night and a double has started to feel cramped, especially if one of you keeps different hours and the other feels every exit. It also suits you if one partner is on the taller side, since the 200cm length gives feet somewhere to go, or if a dog has quietly claimed a share of the mattress and 135cm no longer stretches to three.
Consider another size if...
Your bedroom can't comfortably take a king; we suggest allowing at least 2.7m x 2.9m. If that's tight once wardrobes are in, we'd recommend the UK double instead, which needs around 2.6m x 2.8m.
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FAQ's
Is the Silentnight 3 Zone Memory Foam Mattress in a UK king big enough for a couple?
Yes, comfortably for most. The UK king measures 150 x 200cm, which gives 75cm each for two people sharing. That's a meaningful step up from a double, and because this is a firm memory foam mattress with little bounce, the extra width does more for comfort than a softer surface would.
Will a UK king help if my partner wakes me getting up early?
It helps twice over. Memory foam absorbs movement rather than passing it across the bed, so someone leaving at 5am creates less ripple than they would on springs. Add the extra width of the UK king and the person getting up can slide out from their own side without crossing yours.
Is the UK king long enough for someone over six foot?
At 200cm, the UK king is 10cm longer than the UK Double, and that extra length is often the real reason taller sleepers upgrade. The firm feel also means less sinking at the heels and shoulders, so the full length stays usable rather than swallowing you into the middle.
What room size do I need for this mattress in a UK king?
We suggest allowing at least 2.7m x 2.9m, and that's our guidance rather than Silentnight's. New build master bedrooms can be smaller than they first appear once wardrobes go in, so measure the floor space that's actually left before committing. If it's marginal, the UK double needs around 2.6m x 2.8m.
How do I find the best price on the Silentnight 3 Zone in a UK king?
Use the price table on this page. The prices shown here are updated as retailers change them, so it reflects what the UK king actually costs today rather than a headline figure. King is typically mid-table in a mattress range's pricing, above the UK double but well below the UK super king.