Silentnight Double Sided Miracoil Mattress
Mattress
Silentnight Double Sided Miracoil Mattress
Size
Firmness
Construction
Depth (cm)
24
Layers
3
Layer Details
- Cover. A soft knitted cover that is highly breathable, which means less heat trapped at the surface. It feels soft to the touch rather than stiff or papery.
- Comfort Fillings. Air Plus fibres, breathable comfort fibres that encourage airflow through the mattress. In practice that helps keep the sleep surface feeling fresher through the night.
- Support System. Silentnight's Miracoil spring system, a zoned open coil unit designed to support all parts of the body with individual sleeping zones. The no roll-together design means you are less likely to drift into your partner's side.
- Base Note. The mattress is double sided, so you can flip it to even out wear over time. It arrives flat rather than rolled and boxed, which spares the springs any compression.
Layer details from mattressnextday.co.uk product page, September 2026.
- Room to sleep apart, together: At 15cm wider than the UK double, the UK king gives each of you a defined side, so an early alarm on one side disturbs the other less.
- Zoned springs across a wider bed: The Miracoil system supports individual sleeping zones, which means the extra width is properly supported edge to edge rather than sagging toward the middle.
- Extra length for taller sleepers: The UK king is 10cm longer than the UK double at 200cm, a genuine relief if one of you is approaching six foot.
- Less roll-together where it counts: The no roll-together design means you're less likely to drift into your partner's space, and at this width there's more space to keep.
- Flippable, so the wear spreads: Two people settle into two spots on a king; the double sided build lets you flip it to even out those dips over time.
- Cooler across a bigger surface: Air Plus fibres encourage airflow through the mattress, helpful when two bodies are warming 150cm of sleep surface all night.
This size suits you if...
You share the bed every night and a UK double has started to feel like a negotiation, or one of you keeps different hours and you want an exit and entry that goes unnoticed. It also suits couples where one partner is tall, since the 200cm length gives feet somewhere to go, or households where the dog has quietly claimed a corner and you'd like your own back.
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 and don't need the width. In either case we'd recommend the UK double instead, which needs at least 2.6m x 2.8m.
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Is a UK king Silentnight Miracoil good for couples?
It's a sensible pairing. The UK king gives 75cm each for two people sharing, and the Miracoil springs are a zoned, no roll-together design, so you're less likely to feel a partner shifting or drift into their side. Lightweight side sleepers may find the medium-firm feel slightly too firm, though, so factor in how you both sleep.
Will the Silentnight Double Sided Miracoil UK king fit my bedroom?
The mattress measures 150 x 200cm, or 5ft x 6ft 6in. We suggest a room of at least 2.7m x 2.9m so you can walk round the bed and open drawers without shuffling sideways. New build master bedrooms often shrink once fitted wardrobes go in, so measure the usable floor, including the swing of any doors.
Is the UK king long enough for someone over six foot?
It should be for most. At 200cm, the UK king is 10cm longer than the UK double, which is often the difference between feet on the mattress and feet hanging off the end. If you're well over six foot, the UK super king is the same length, so sizing up buys width rather than extra legroom.
How does this mattress arrive in a king size?
Flat, rather than rolled and boxed, which spares the Miracoil springs any compression. The practical consequence is that a 150 x 200cm mattress has to go up your stairs and round your landing at full size, so check tight corners and doorways before ordering, especially in older houses with narrow staircases.
Is a UK king harder to flip than a smaller size?
It takes two of you, realistically. The double sided design is one of this mattress's genuine strengths, letting you even out wear where each sleeper settles, but a 150 x 200cm mattress is awkward for one person to turn. Since a UK king usually means a sharing couple, that's rarely a problem in practice.