Last seen for £449 at Mattress Man on 10th November 2026
Silentnight Memory 3 Sleep Super King Mattress
The Silentnight Memory 3 Sleep Mattress is a memory foam mattress from one of Britain's best-known bed brands.
- Medium feel for most sleepers
- Memory foam softens pressure points
- Fits UK & EU bed frames
Save with the previous model
Some retailers still sell the earlier version of this mattress for less than the current model's best price.
More available sizes
Last seen for £395 at Mattress Man on 10th November 2026
Last seen for £449 at Mattress Man on 10th November 2026
Last seen for £395 at Mattress Man on 10th November 2026
Last seen for £335 at Mattress Man on 10th November 2026
Last seen for £345 at Mattress Man on 10th November 2026
Last seen for £255 at Mattress Man on 10th November 2026
Last seen for £249 at Mattress Man on 10th November 2026
Mattress details
Mattress
Silentnight Memory 3 Sleep Mattress
Size
Firmness
Medium
Construction
Foam
Memory Foam
Depth (cm)
Layers
2
Layer Details
Foam layer (top)
The first of two foam layers in an 18 cm mattress. Together they give the medium feel, with memory foam that softens as it warms and gives your hips and shoulders a gentler landing.
Foam layer (base)
The second foam layer sits beneath the first. It is part of an all-foam build, so you get a steady, sprung-free feel rather than the bounce of a pocket spring mattress.
Layer details from mattressman.co.uk and robertdyas.co.uk product pages, October 2026.
Key benefits
- 90cm each when you share: Two people sharing get 90cm each, which means a partner who turns over a dozen times a night becomes far easier to sleep through.
- Foam that keeps movement local: Memory foam moulds around each sleeper rather than bouncing, so on a bed this wide a fidgeter on one side barely registers on the other.
- Room for the whole household: When children arrive at 3am, the extra width means everyone still gets a genuine share rather than one adult clinging to the edge.
- 30cm wider than a UK king: The UK super king is 30cm wider than the UK king at the same length, and that extra width is the whole point of paying more.
- Affordable at the biggest size: Silentnight prices this model modestly for a big-brand memory foam mattress, so going up to a UK super king stays within reach; compare the retailers listed on this page.
This size suits you if...
You share the bed every night and want enough width that neither of you notices the other, your children or pets treat your bed as communal territory, or your master bedroom is large enough that a UK king would look lost in it. Allow at least 3m x 2.9m of floor space, with a bit more feeling comfortable once you add bedside tables and walking room.
Consider another size if...
Your bedroom falls short of the 3m x 2.9m we suggest for the UK super king, or you're squeezing past the bed to reach the wardrobe. The UK king would suit you better; we suggest at least 2.7m x 2.9m for that size.
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FAQ's
What room size do I need for a super king Silentnight Memory 3?
We suggest at least 3m x 2.9m for the UK super king. That allows the mattress itself plus space to walk round and open doors. Measure the door swing and any landing turns too, because at 180 x 200cm this is a large item to move upstairs, even though foam mattresses flex more than sprung ones.
Is the Silentnight Memory 3 super king big enough for co-sleeping with kids?
It's the best mainstream option for it. With 90cm each for two adults sharing, there's meaningful room left when a child climbs in, rather than everyone shuffling to the edges. Memory foam also softens the disruption when they arrive, since it doesn't transfer movement the way a bouncier sprung mattress would.
How much wider is the super king than the king in this mattress?
The UK super king is 30cm wider than the UK king, and the two are the same length. That 30cm sounds modest on paper, but split between two sleepers it's the difference between feeling every turn your partner makes and sleeping through it. If your room can take the width, it's usually worth having.
Will the Memory 3 super king suit a restless partner?
This is the size we'd point restless couples towards. Distance does more than any comfort layer, and 90cm each means most movement simply happens too far away to wake you. The memory foam helps as well, since it absorbs motion rather than passing it across the bed. A lighter sleeper next to a fidgeter benefits most.
What bedding does the super king size need?
You'll need super king sheets and we'd suggest a 260 x 220cm duvet, which costs a little more than double or king bedding, so factor that into the total. On the upside, a generously overhanging duvet at this width means the end of one person hogging it, which for many couples is half the reason for sizing up.