Sealy Advantage Classic Mattress
Mattress
Sealy Advantage Classic Mattress
Size
Firmness
Construction
Depth (cm)
24
Layers
4
Layer Details
- Quilted Cover. The cover and fillings are stitched together into a patterned comfort quilt, which means the soft top layer stays put rather than shifting over time. It gives that traditional, gently cushioned surface feel.
- Zoned Foam. This layer targets key areas of your body and applies support where you need it most. In practice that means firmer backing under heavier zones like your hips, with a little more give elsewhere.
- Reflex Foam. Reflex foam is a firmer, springier foam used here between the comfort layers and the springs. It adds a stable, comfortably supportive middle so you don't feel the coils directly.
- PostureTech CS Springs. These open coil springs are weight responsive, getting firmer as pressure increases, which means deeper support under the parts of you that need it. Sealy describes this as deep down support that's designed to last.
Layer details from mattressnextday.co.uk product page, September 2026.
- 90cm each for two sharing: Each of you gets 90cm of width, which means a partner who turns over frequently sits far enough away that you're less likely to feel it.
- Distance offsets the open coil feel: PostureTech CS springs share movement across the bed more than pocket springs do, so the extra width of the UK super king is genuinely useful rather than a luxury.
- 30cm wider than the UK king: The UK super king adds 30cm of width over the UK king at the same length, which is roughly a child or a large dog's worth of extra space.
- Zoned support that scales with the load: The springs firm up as pressure increases, so two adults of different weights each get support matched to where they sit heaviest.
- Room for the whole household: If children wander in during the night, or the dog treats the bed as its own, 6ft x 6ft 6in leaves everyone a workable share.
This size suits you if...
You share the bed every night and one of you is a light sleeper, since the extra width compensates for the movement an open coil system carries across the surface. It also fits if your children or pets regularly end up in the bed by morning, or if you have a large master bedroom where a UK king would look a little lost.
Consider another size if...
Your bedroom falls short of the 3m x 2.9m we suggest for the UK super king. The UK king would suit you better: it's the same length, 30cm narrower, and we suggest at least 2.7m x 2.9m for it.
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Is the Sealy Advantage Classic super king good for couples?
Yes, and arguably it's the size where this mattress makes most sense for two. The open coil springs carry movement across the bed more than pocket springs would, so a restless partner is easier to notice on a narrower size. At 90cm each for two people sharing, most of that disturbance simply happens further away from you.
Will the Sealy Advantage Classic super king fit in my bedroom?
We suggest a room of at least 3m x 2.9m for a UK super king, which leaves walking space around the bed and room for doors and drawers to open. Measure before you order, and check the route in too: landings with tight turns and narrow door swings are where a mattress this size gets stuck.
How much space do you get on a super king Sealy Advantage Classic?
The UK super king measures 180 x 200cm, or 6ft x 6ft 6in, which works out at 90cm each for two people sharing. That's the same width per person as a UK single, so each of you sleeps as if you had the bed to yourself, with the zoned foam supporting each sleeper independently of the other's weight.
Is the super king longer than the king in this mattress?
No. The UK super king and the UK king are the same length at 200cm; the difference is width, with the UK super king 30cm wider. So if you're choosing between the two, it's a question of how much sideways space you want, and whether your room can take the wider footprint.
Does this size suit sharing with children or pets?
It's the best size in the range for it. Children who arrive at 3am, or a large dog that considers the bed shared territory, eat into your space quickly on a UK double or UK king. The 180cm width of the UK super king means everyone still gets a reasonable share, and the weight-responsive springs firm up wherever the load lands.