Super King Mattresses in Memory Foam and Pocket Sprung
The super king is 6ft x 6ft 6in (180 x 200cm), and the step up from a king is 30cm — twice the gap between any other two UK sizes. It is the same length as a king, so this is purely about width.
Two people on a super king get 90cm each, which is exactly what one person gets on a single bed. That is the whole appeal, and it is also the reason the room has to be right: at 180cm wide, an ordinary UK bedroom can end up with a bed and very little else.
Memory foam super king mattresses
Foam forms to the sleeper and spreads their weight instead of resisting it at the hips and shoulders.
Across this width it does something no other construction manages as well: it isolates each side almost completely. With 90cm each and foam underneath, one person getting up at six in the morning is genuinely unnoticeable on the other side of the bed.
Foam holds warmth, and a surface this large with two people on it holds a good deal. The versions made with gel through the layer sleep noticeably cooler and are worth looking at for a warm room.
Pocket sprung super king mattresses
Each spring sits in its own fabric pocket and compresses independently of the ones beside it.
On a superking that independence matters for a practical reason: a mattress this wide has to hold its shape across a long unsupported span, and pocket springs do that without the whole surface moving as one piece. Two people of different weights each get the support they need, and neither rolls towards the middle.
Air moves between the pockets, so these run cooler than foam. Where a mattress carries a pillow top, that is a padded layer stitched over the springs, softening the surface without changing the support beneath.
Firm super king mattresses
Firm holds the body higher and lets it sink in less; softer lets the shoulders and hips settle further before taking the weight. Back and front sleepers and heavier sleepers generally want firmer, side sleepers less.
At this width, two people can genuinely have different preferences without either compromising, because there is enough distance between them that the surface does not have to be a single average. Where the difference is large, a medium-firm mattress with a topper on one side does the job.
Super king mattress FAQs
What size is a super king mattress?
6ft x 6ft 6in, or 180 x 200cm, in the UK and Ireland.
What is the difference between a king and a super king?
Width only. A super king is 180cm against the king's 150cm, and both are 200cm long. That 30cm gives each of two sleepers 90cm rather than 75cm.
Is a super king the biggest UK bed size?
It is the largest standard size. Larger beds exist under names like emperor, but they are made to order rather than stocked, and bedding for them is difficult to find.
Is a super king the same as an American king?
Close but not the same. An American king is roughly 193 x 203cm, slightly wider and longer, so the mattress and the bedding are not interchangeable with a UK super king.
Will a super king mattress fit up my stairs?
At 180cm it is the hardest size to get into an upstairs bedroom, and a staircase with a half landing often will not take it in one piece. Measure the narrowest turn before ordering. A zip and link mattress, which is two narrow mattresses joined down the middle, is the usual answer where access is tight.
What size bedding does a super king need?
Super king specifically. A king duvet is 30cm too narrow and leaves one person uncovered, and a king fitted sheet will not reach.