King Size v Super King Size - What's the Difference?

Updated 2026: Choosing between a king-size and a super king-size mattress comes down to a handful of practical factors rather than one being simply better than the other. This guide walks through the decision itself, if you want the full centimetre by centimetre breakdown of every UK bed size, our bed sizes guide covers that in full.

King Size and Super King Size at a Glance

A UK king size mattress measures 150cm wide by 200cm long. A super king size measures 180cm wide by 200cm long, the same length but 30cm wider, roughly the length of a large office ruler. That extra width is the entire difference in dimensions, and it changes more about the sleeping experience than the numbers alone suggest.

Our Artisan Naturals mattress, one of our best selling ranges, is priced at £2,180 in king size and £2,590 in super king, a useful reference point if you’re weighing up the cost difference alongside the space difference.

Which Size Is Right for You?

Four things tend to decide this for most people, and it is worth working through them in order rather than picking on space alone.

Room size

A super king needs noticeably more floor space, both for the bed itself and for the clearance around it to open wardrobes and walk comfortably. If you are at all unsure whether your room can take one, our bed size guide for choosing a mattress for your room covers minimum room dimensions for every size.

Delivery access

Tight stairwells, 180 degree turns or narrow doorways can rule out a one piece mattress in either size. This does not rule out a super king altogether though, a zip and link model, built in two halves, gets around most access problems that would stop a one piece mattress going up the stairs.

How you sleep

If you tend to stay near the edge of the mattress and rarely move into the centre, a super king can be the wrong choice rather than the better one. The unused centre of a wide mattress gets little to no use over time, and that can lead to settlement and indents forming where the edges are used constantly and the middle is not. A zip and link super king solves this, since each half can be turned individually, so both sides of each mattress actually get used.

Monthly turning and rotation

Every two sided mattress needs turning and rotating monthly to wear evenly and meet the guarantee terms. A super king can weigh upwards of 80kg once it is packed with natural fibre fillings and calico encased pocket springs, which realistically needs two people to manage. A zip and link configuration splits that weight in half and makes the job manageable for one person.

Benefits and Drawbacks of a King Size Mattress

• Enough room for two adults to sleep without disturbing each other
• Suits a wide range of sleeping positions
• Fits a wider range of bodyweights and heights than a double
• Can feel a little tight for very active sleepers who move around a lot
• May look out of proportion in a very large bedroom
• Not every bed frame can accommodate a one piece king size

Benefits and Drawbacks of a Super King Size Mattress

• Enough space to roll over twice before meeting your partner in the middle
• Comfortably suits any sleeping position, side, back or starfish
• Enough room for children or pets to join you without anyone feeling cramped
• Access issues cause more one piece delivery failures than with a king size
• The unused centre of the mattress can form a ridge over time if you both sleep at the edges
• Bedding is bulkier and can be awkward to fit and wash
• Most bedrooms cannot fit a super king with enough space left to move around comfortably

Frequently Asked Questions

What is the actual size difference between king and super king?

There is a 30cm difference in width between the two, king size is 150cm wide and super king is 180cm wide. Both are the same length, 200cm. That 30cm gives each sleeper an extra 15cm of personal space on a super king compared to a king size.

Is a super king always better than a king size?

Not necessarily. A super king suits larger bedrooms, taller or larger framed sleepers, and couples who want maximum separation during the night. A king size suits smaller rooms, easier delivery access, and couples who sleep closer to the centre of the mattress rather than at the edges. Bigger is not automatically better if the room or the sleeping habits do not suit it.

Can a super king mattress go up a narrow staircase?

A one piece super king can struggle with tight stairwells, 180 degree turns or narrow doorways. A zip and link mattress, built as two separate halves, gets around this in most properties where a one piece mattress would not fit.

Do I need to turn a super king mattress differently to a king size?

The turning schedule is the same, monthly, for both sizes on a two sided mattress. What changes is the weight involved, a super king can weigh upwards of 80kg, which needs two people to turn safely. A zip and link super king splits that weight across two smaller mattresses, making it manageable for one person.

Summary

If your bedroom is large enough, you are an active sleeper who moves around a lot, or you simply want the extra space, a super king is worth the jump up from king size. We would always recommend a zip and link model for either size if delivery access or monthly turning is a concern, since it solves both problems without giving up any of the comfort.

It is always worth checking your room size and access before committing to a one piece mattress in either size. Still unsure which is right for you? Give our small expert team a call for free advice on 0161 437 4419.