Sealy Posture Balance Single Mattress
The Sealy Posture Balance comes in five UK sizes, from Single up to Super King.
- Firm feel with cushioned comfort
- Open-cell foam for breathability
- Hypoallergenic fibre fillings
£643.50
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Sealy Posture Balance Mattress
More available sizes
Mattress details
Mattress
Sealy Posture Balance Mattress
Size
Firmness
Firm
Construction
Depth (cm)
Layers
3
Layer Details
PostureTech 2.0 pocket springs
Pocket springs made with higher gauge wire sit at the heart of this firmer design. They give the mattress its supportive base feel, which suits sleepers who like a firm, steady surface.
MicroCell
An open-cell foam that is durable and resilient, with a soft feel. The open structure helps air move through, so it should sleep less warm than a dense foam.
OptiForm firm foam
A double layer of firm foam that gently cushions and adapts to your body. It adds some give on top of the firm feel, so the surface isn't hard.
Layer details from mattressman.co.uk product page, October 2026.
Key benefits
- Fits where other sizes won't: At 90cm wide it slots into compact bedrooms and loft rooms with a narrow footprint, and we suggest as little as 2.1m x 2.8m of floor space.
- Leaves room for the rest of the furniture: In a child's room where the bed competes with a desk, wardrobe and toy storage, the single's slim width keeps usable floor free.
- Works for shared kids' rooms: Two UK singles plus a walkway fit in rooms where anything wider would rule out the second bed entirely.
- Cheap, easy bedding: Single sheets and a 135 x 200cm duvet are the most widely stocked and lowest-priced bedding of any UK size, which keeps running costs down.
- A sensible guest room choice: For a spare room that doubles as an office, a UK single leaves space for a desk rather than swallowing the room.
This size suits you if...
You're buying for a child or teenager moving up from a cot or toddler bed, you sleep alone and want to keep floor space free in a small room, or you're furnishing a guest room or student flat where the frame is already a standard UK single.
Consider another size if...
You're an adult who sleeps sprawled, or your room can take something wider. The Sealy Posture Balance in a UK small double gives you 30cm more width at the same length, and we suggest at least 2.4m x 2.8m for it.
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FAQ's
What size room do I need for a UK single Sealy Posture Balance?
We suggest allowing at least 2.1m x 2.8m of floor space. That gives you room to walk around the bed and open drawers or a wardrobe. It's our own guidance rather than Sealy's, and it makes the UK single a realistic fit for box rooms, lofts with a narrow flat section and shared children's rooms.
Will the UK single Sealy Posture Balance fit a bunk or mid sleeper frame?
The 90 x 190cm footprint matches standard UK bunk, cabin and mid sleeper frames, so width and length should be fine. Raised frames also set a maximum mattress depth for safety rails, and Sealy doesn't publish full specifications for this model, so check the depth on the retailer listing against your frame's limit first.
Is a UK single big enough for an adult?
For most single adults, yes: 90cm of width is the standard one-person size and 190cm of length suits anyone up to around average height. Taller sleepers should note the UK king and UK super king are 10cm longer. If you tend to spread out, the UK small double adds 30cm of width at the same length.
What bedding fits the Sealy Posture Balance single?
Standard UK single fitted sheets are made for the 90 x 190cm footprint, and a single duvet at 135 x 200cm is the usual pairing. Both are the cheapest and most widely available bedding of any size, which matters if you're kitting out a child's room or a guest bed on a budget.
How does the single compare with the double in this mattress?
The UK single is 45cm narrower than the UK double, and the two are the same length. For the UK double we suggest a room of at least 2.6m x 2.8m, against 2.1m x 2.8m for the UK single. If the bed is for one person in a modest room, the single usually makes better use of the space.