Sealy Serenity Double Mattress
The Sealy Serenity is a firm mattress built around Sealy's AlignSupport® spring system, an open-coil design exclusive to the brand, topped with foam comfort layers.
- Firm feel for back & front sleepers
- Stable, evenly sprung support
- Foam layers soften the surface
£1,393.15
Get the lowest price we've found
Save with the previous model
Some retailers still sell the earlier version of this mattress for less than the current model's best price.
Sealy Serenity Mattress
More available sizes
Mattress details
Mattress
Sealy Serenity Mattress
Size
Firmness
Firm
Construction
Foam
Open Coil Spring
Depth (cm)
Layers
2
Layer Details
Foam layers
Foam comfort layers sit above the springs, which means a slightly cushioned surface feel over the firm support beneath. They complement rather than mask the spring system below.
AlignSupport® spring system
An open-coil spring system exclusive to Sealy that forms the mattress's supportive core. Open coils give a springy, connected feel across the whole surface, keeping you supported rather than cradled.
Layer details from mattressman.co.uk product page, September 2026.
Key benefits
- Sensible space for two: At 135cm wide you get 67.5cm each for two people sharing, which works well if you both sleep fairly still on your back or front.
- Fits the average British bedroom: We suggest allowing at least 2.6m x 2.8m, so this size leaves walking room where a larger mattress would push against the walls.
- Consistent firmness across the width: The open-coil core gives a connected, evenly sprung feel from edge to edge, which means neither sleeper ends up on a softer patch.
- Easy to dress: Double sheets and a 200 x 200cm double duvet are stocked everywhere at every price, handy if you're furnishing a whole home at once.
- A safe pick for a guest room: The firm, no-sink surface suits visiting couples with different sleep styles, and a UK double still leaves space for a wardrobe and drawers.
This size suits you if...
You share the bed every night and want the traditional couples' size in a room that couldn't take anything bigger, you're kitting out a first flat or guest room and need a size that fits alongside a wardrobe and chest of drawers, or you sleep alone, like a firm surface, and want space to stretch out or share with the dog.
Consider another size if...
You and your partner both move around at night, or one of you is broad shouldered, and 67.5cm each feels tight. We'd recommend the UK king instead: it's 15cm wider and 10cm longer, and we suggest allowing at least 2.7m x 2.9m for it.
Similar Mattresses in This Price Range
Did you know? On Mattress Unboxed we have over 1,000 different mattresses to suit all types of sleepers. View all mattresses.
FAQ's
Is the Sealy Serenity UK double big enough for a couple?
For most couples, yes. The 135 x 190cm footprint gives 67.5cm each for two people sharing, and the firm surface stops you rolling towards each other. One caveat: open coils are connected, so you'll feel a restless partner's movement more than you would on pocket springs. Still sleepers will be fine; fidgety pairs should think about more width.
Will the Sealy Serenity UK double fit a room with bedside tables on both sides?
Usually. We suggest a minimum room of 2.6m x 2.8m for a UK double, and around 3m x 3m is the comfortable norm if you want a table either side plus space to walk around the foot of the bed. Measure with the tables in place before you order, especially in a smaller second bedroom.
Should I buy the Sealy Serenity in a UK double or a UK king?
The UK double is 15cm narrower and 10cm shorter than the UK king. Choose the UK double if your room is modest or you're also buying furniture and bedding on a spread budget. Choose the UK king if you're tall, share with a restless partner, and can allow at least 2.7m x 2.9m of floor space.
Is a UK double Sealy Serenity a good choice for a guest room?
It's a solid one. The size takes visiting couples without swallowing the room, and the firm, supportive feel is a safe middle ground for guests whose preferences you don't know. Lightweight side sleepers may find it a little unforgiving around the shoulders, so it's better suited to occasional stays than to a side sleeper's everyday bed.
What bedding do I need for the Sealy Serenity UK double?
Standard UK double bedding: sheets sized for a 135 x 190cm (4ft 6in x 6ft 3in) mattress and a 200 x 200cm double duvet. Because the double is the long standing UK standard, you'll find bedding for it in every shop at every price point, which makes it the cheapest size to dress and re-dress over the years.