Superking vs King Size Mattress: Is the Extra Width Worth It?

Bed Kingdom guide · Updated October 2026 · 4 min read

A superking mattress measures 180x200cm while a standard king is 150x200cm. For larger households and couples in the UK this extra space can reduce disturbance at night, yet it demands a bigger bedroom, larger bedding and higher cost. This guide sets out the practical differences so you can decide whether the additional width justifies the investment.

Size Specifications and UK Bedroom Fit

UK king size mattresses are 150x200cm (5ft). Super king versions are 180x200cm (6ft). Both share the same length, so the only change is width. Measure your bedroom carefully: allow at least 60cm clearance on each long side for bedside tables and movement. A superking needs roughly 3m of clear wall space once the bed frame and tables are in place, while a king needs about 2.7m.

Many UK homes built before 2000 have main bedrooms around 3.5m by 4m. In these rooms a king leaves more space for wardrobes and chest of drawers. A superking can feel cramped unless the room is at least 4m wide. Always mark the floor with masking tape using the exact dimensions before buying.

Space for Sleepers and Real-World Comfort

Each adult on a king mattress has 75cm of personal width. On a superking this rises to 90cm. Couples who share a bed with a child or large dog often find the extra 30cm total width transforms sleep quality. Side sleepers who spread their arms benefit most. If you both sleep on your backs the difference is smaller.

Practical test: lie on your bed at home and stretch both arms sideways. If your fingertips touch your partner, the extra width of a superking will help. Larger households with teenagers who occasionally share the parental bed also gain from the 180cm platform.

Bedding Availability and Extra Costs

King-size fitted sheets, duvets and duvet covers are widely stocked in the UK. Superking options are fewer and usually more expensive. A superking duvet is easy to find but matching pillowcases and valances can require specialist retailers. Check current stock on the duvets and duvet covers & sets pages before choosing size.

Replacement costs add up. A good king-size mattress protector costs less and is replaced more easily than a superking version. Factor this into your budget for the first five years of ownership.

Cost Comparison and Value

Superking mattresses are typically more expensive than the same model in king size because they use more foam, springs and fabric. The bed frame follows the same pattern. A king-size ottoman bed is cheaper and leaves money for better quality mattresses or bedside tables.

If your current bedding and frame are already king size, switching to superking means buying everything again. For many couples the extra width is worth the cost only if they have slept in both sizes and noticed a clear improvement in sleep quality.

Mattress Types and Recommendations

The extra width of a superking benefits most from supportive constructions that prevent roll-together. Pocket sprung and hybrid mattresses perform well because the independent springs limit motion transfer across the wider surface.

Consider these models that suit the comparison:

• Maxitex Diamond Dual Season 1000 Pocket Memory Mattress – offers balanced support that works equally on a 150cm or 180cm platform.
• Maxitex Hybrid 3000 Pocket Sprung Memory Mattress – combines springs and foam for reduced partner disturbance, especially useful on the wider superking.
• Noomi Bamboo Natural Latex Pocket Sprung Mattress – natural materials that stay cool across the full 180cm width.
• Maxitex Natural 3000 Mattress – eco-friendly choice that maintains consistent firmness whether used on king or superking beds.

View the full range of king size mattresses or super king mattresses to compare depths and firmness ratings side by side. Memory foam and pocket sprung options are both popular; choose according to whether you prefer a cooler or more cushioned feel.

Frame and Storage Considerations

King size beds have more frame styles available, including ottoman designs that provide useful under-bed storage. Super king ottoman beds exist but cost more and need a larger floor area when the base lifts. If storage is a priority, compare king size ottoman beds against super king ottoman beds.

Measure your stairs and doorways before ordering a larger frame. A dismantled superking bed still requires more clearance than a king.

Decision Checklist

Use this list to reach a clear choice:

1. Measure bedroom width and length; subtract furniture and clearance space. Can a 180cm mattress fit comfortably?
2. Do you and your partner currently disturb each other more than twice per night?
3. Calculate the price difference for mattress, bed, bedding and protectors. Is the extra cost under for the full set?
4. Check duvet and sheet availability in superking size for your preferred brands.
5. Visit the showroom in Birstall, West Yorkshire to lie on both sizes on similar bases.

If three or more answers favour the larger size, choose superking. Otherwise the standard king offers better value for most UK homes.

Both sizes meet UK fire-safety regulations (BS 7177). All bunk beds sold must meet BS EN 747 with guard rails rising at least 16cm above the mattress; top bunks are not recommended for children under 6. These rules apply equally whether you choose king or superking in a family setting.

For smaller rooms or first homes the king size remains the practical choice. Larger master bedrooms with space for bedroom furniture can accommodate the extra width and gain genuine comfort. The final decision rests on accurate room measurements and honest assessment of how much you value those additional 15cm per side.

Frequently asked questions

Can two single mattresses make a superking size?

Two single 90x190cm mattresses placed side by side create 180x190cm, which is 10cm shorter than a true superking (180x200cm). Most couples notice the join and the length shortfall. A purpose-made superking mattress avoids gaps and provides consistent support across the full width.

What size duvet fits a superking mattress?

A 200x220cm duvet is the standard size for a UK superking mattress. This gives 20cm overhang on each side of the 180cm width. King-size duvets (200x200cm) are too narrow and leave the edges uncovered. Always confirm exact duvet dimensions before purchase.

Is a superking mattress too big for a standard UK bedroom?

It depends on the room. A bedroom at least 4m wide by 4.5m long can fit a superking bed plus two bedside tables and still allow 60cm walkways. Smaller rooms of 3.5m width usually feel cramped. Always measure twice and mark the floor outline before ordering.

Do superking beds cost a lot more than king size?

Mattresses and frames in superking size are typically more expensive due to extra materials. Bedding and protectors follow the same pattern. Weigh this against the space gained.

Which firmness is best for a superking mattress?

Medium to firm ratings suit most couples on a wider bed because the larger surface can feel softer. Test firmness in store on a similar size base. Pocket sprung and hybrid constructions maintain support better across 180cm than all-foam designs.

Related guides

• King Size Bed Pros and Cons: Is It Worth It
• Super King Mattress vs Emperor Mattress: Luxury Size Guide
• King Size vs Super King Mattress: Depth and Comfort Guide
• Latex Hybrid Mattresses: Are They Worth It?
• Single vs Small Double Mattress: Which Size Should You Choose?
• Euro Double vs UK Double Mattress: Size and Fit Guide

Browse all Bed Kingdom guides and quizzes