Sealy Tranquility Super King Mattress
Sealy

Sealy Tranquility Super King Mattress

The Sealy Tranquility is an extra firm mattress built on Sealy's AlignSupport spring system with foam layers on top.

  • Properly extra-firm feel
  • AlignSupport springs for spinal support
  • Foam layers take the edge off

£1,852.15

Size: Super King. Available at Mattress Man

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Where can I buy the Sealy Tranquility Super King Mattress?

Below are the best prices for the Sealy Tranquility Mattress in a Super King. Available from (9) trusted retailers.

Sealy Tranquility Mattress

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Prices last checked:
11th November 2026

Mattress dimensions for the Sealy Tranquility Super King Mattress

Length: 200cm

Width: 180cm

(6ft x 6ft 6in)

Minimum room size: 3m x 2.9m

Mattress details

Mattress Details for the Sealy Tranquility Super King Mattress

Mattress

Sealy Tranquility Mattress

Size

UK Super King (6ft x 6ft 6in)

Firmness

Extra Firm

Construction

  • Foam

Depth (cm)

Layers

Layer Details

Key benefits

Key Benefits of the Sealy Tranquility Super King Mattress

  • 90cm each for two sharers: With 90cm each for two people sharing, you can both stretch out fully without ever negotiating for space.
  • Distance beats any comfort layer: On an extra firm surface with minimal sink, a fidgeting partner is mostly a proximity problem, and 180cm of width solves it better than foam ever could.
  • Room for night-time visitors: A child padding in at 3am, or a large dog treating the bed as theirs, no longer forces anyone to the edge.
  • Firm support across the full width: Sealy's AlignSupport spring system keeps the surface consistent edge to edge, which means the same solid feel wherever you end up sleeping.
  • The largest standard UK size: The UK super king is 30cm wider than the UK king, and it is the biggest size stocked as standard, so bedding and bases remain easy to find.

Who should buy the Sealy Tranquility Super King Mattress?

This size suits you if...

You share every night and want the maximum mainstream size, you sleep next to someone genuinely restless and need distance rather than dampening, or your bed regularly hosts children or pets on top of two adults. You will also both need to like an extra firm feel, since there is no soft side to retreat to. Allow at least 3m x 2.9m of floor space, ideally more.

Consider another size if...

Your bedroom falls short of the 3m x 2.9m we suggest as a minimum, or the extra width would go unused. The UK king would suit you better: it is the same length, and we suggest at least 2.7m x 2.9m for it.

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FAQ's

Frequently Asked Questions About the UK Super King

Is the Sealy Tranquility super king a good choice for restless couples?

Yes, arguably the best size for it. An extra firm mattress transfers less bounce than a soft one to begin with, and 90cm each for two people sharing means most movement happens too far away to notice. If one of you tosses and turns, the width does more for the other person's sleep than any comfort layer.

What room size do I need for the Sealy Tranquility super king?

We suggest at least 3m x 2.9m, with around 3.5m x 3.2m feeling comfortable. That allows walking space on both sides and room for the door to swing. In a large master or a period property with generous proportions, a UK king can look undersized, and the super king fills the space properly.

Should I buy the Sealy Tranquility in a UK king or super king?

The UK super king is 30cm wider than the UK king, and the two are the same length. If children or pets join you at night, or one of you is a restless sleeper, that extra width is the whole point. If your room is under 3m x 2.9m, the UK king is the sensible call.

Is a super king wide enough to share with children?

It is the size we would point parents towards. At 180cm wide, two adults and a visiting child can all keep a reasonable share, which is rarely true of a UK double. One caveat with this model: the Tranquility is extra firm, so younger children used to a softer surface may notice the difference.

Where can I buy the Sealy Tranquility super king?

Compare the retailers listed on this page; the prices shown here are updated as retailers change them. Before ordering, measure your staircase and landing turns, because a 180 x 200cm sprung mattress is heavy and awkward to manoeuvre, and check the doorway of the room it is destined for.