What Are the Sizes of King Beds?

King Bed Sizes at a Glance

In the UK, a king size bed measures 150cm wide by 200cm long, or 5ft by 6ft 6in. A super king size bed measures 180cm by 200cm, or 6ft by 6ft 6in. Those two dimensions cover the vast majority of king beds sold in Britain. If you see a bed described simply as king size in a UK shop, it will be 150cm by 200cm unless clearly stated otherwise.

The confusion usually arrives from overseas sizing. American and continental European beds use different measurements, and mattresses bought abroad rarely match UK frames or bedding. Knowing which system you are working in prevents the most common and most expensive mistake in bedroom furnishing.

UK King Size in Detail

The standard king mattress at 150cm by 200cm gives two sleepers about 75cm of width each. The 200cm length is the same as super king and emperor sizes, so anyone moving up from a double at 190cm long gains 10cm at the foot regardless of which large size they choose.

Frames add to the external footprint. Depending on construction, the outer width of a king size frame typically ranges from about 155cm for a slim wooden design to around 172cm for a deeply padded upholstered one. Length follows the same logic, particularly where a headboard is thick or the frame has a footboard. Always work from the manufacturer external dimensions rather than the mattress size when checking a room.

Super King and Beyond

Super king at 180cm by 200cm is the next step up and is increasingly common in newer homes with larger main bedrooms. The 30cm gain over a king is substantial: each sleeper effectively has the width of a small single. It suits couples who want genuinely independent space, and it works well in rooms wide enough to keep walkways at 70cm or more on both sides.

Above super king, sizing becomes less standardised. Emperor beds usually measure around 200cm by 200cm, though some makers produce 180cm by 220cm variants for taller sleepers. Because these sizes vary between manufacturers, bedding needs to be matched to the specific mattress rather than bought on the label alone.

How International Sizes Compare

A US king measures approximately 193cm by 203cm, which is closer to a UK super king in width but slightly longer. A US queen at roughly 152cm by 203cm is almost the same width as a UK king but 3cm longer, which is enough to make fitted sheets sit badly. European sizing often uses 160cm by 200cm or 180cm by 200cm, sold in two separate mattresses on one frame.

The practical takeaway is straightforward: buy the frame, mattress and bedding within a single sizing system. Mixing systems leads to sheets that will not tuck, mattresses that overhang the frame edge, and slats that do not align with the mattress footprint.

Choosing Between King Sizes for a UK Bedroom

Room dimensions decide this more than preference does. As a rough guide, a king size bed suits a bedroom from about 3m by 3.4m upwards. A super king starts to make sense from around 3.4m by 3.6m, and comfortably so beyond that. Below those figures, the bed will fit but the room will feel tight and everyday movement becomes awkward.

Door swings, radiators and window positions all reduce usable width. Measure to the skirting and note anything that projects into the room. If a wardrobe door opens towards the bed, check the arc, since a 60cm deep door needs 60cm of clear floor. Sliding door designs in our modern sliding wardrobes UK sale avoid that problem entirely and are often the difference between a king fitting well and only just fitting.

Frame Materials in King and Super King

Once you know the size, material shapes the character of the room. Wooden frames read as calm and structural, and pale finishes keep a large bed feeling light. Our king size wooden beds UK sale range from simple slatted designs to solid panelled headboards.

Upholstered fabric brings softness and sound absorption, useful in rooms with hard flooring. Leather has a smoother, more formal presence and wipes clean easily. If you are going straight to the larger size, our super king size fabric beds UK sale selection covers low profile and tall headboard styles.

Storage frames deserve a mention because they change the maths on the rest of the room. Ottoman and drawer bases in king or super king hold a surprising volume, which can remove the need for a second chest of drawers in a room where the bed already takes the majority of the floor.

Bedding, Mattresses and Practicalities

King and super king bedding are both readily available in the UK. Duvets follow the mattress width closely, and choosing the correct one prevents the shortfall that happens when a double duvet is stretched across a wider bed. Mattress protectors and fitted sheets need to match mattress depth as well as width, especially with hybrid constructions that can exceed 30cm.

Access matters too. A super king mattress is heavy and does not bend, so measure stairwells, landings and door frames before ordering. Frames usually arrive flat packed and assemble in the room, which sidesteps the problem, but a one piece mattress cannot be reduced in size.

Ventilation and support are worth checking. Wider frames should include a central support rail with at least one additional leg, because unsupported slats across a 180cm span will eventually sag. Most reputable frames include this as standard.

Building the Rest of the Room Around the Bed

With a large bed in place, everything else needs to work harder in less space. Narrow drawers with a taller profile store more per square metre than wide, low units, and our modern chest of drawers UK sale includes both proportions so you can pick what the floor plan allows. A full length mirror positioned to reflect the window will also open up a room that a super king has visually filled.

If you want the whole scheme to match, modern bedroom collections UK sale keep finishes and handle details consistent across the bed, cabinets and wardrobe. You can shop modern furniture UK with free delivery to most UK mainland postcodes at Furniture in Fashion.

Zip and Link: A Size Option Worth Knowing

Zip and link mattresses are two separate mattresses, usually 75cm or 90cm wide, joined by a zip along the long edge to form a king or super king surface. Two 75cm halves make a 150cm king. Two 90cm halves make a 180cm super king.

The format solves several problems at once. Each half can have a different firmness, which suits couples with very different weights or support needs. The halves travel narrow staircases easily, which is often the deciding factor in a Victorian terrace or a loft conversion. And rotating a 75cm or 90cm mattress single handed is realistic in a way that turning a full super king is not.

The compromise is the join. A good zip and link set with a proper bridging pad is barely noticeable, but a sleeper who habitually lies in the centre of the bed may feel it. If you sleep towards your own side, which most couples do, the seam sits under nobody.

Headboard Height and Wall Proportion

Once you are working at king size or above, headboard height affects how the room reads more than the bed width does. A tall headboard of 120cm or more gives a room a clear focal point and works well under a high ceiling, particularly in period properties with generous wall height.

In a modern build with a ceiling around 2.4m, a tall headboard can crowd the wall and make the room feel shorter than it is. A mid height headboard between 90cm and 105cm usually sits better. Under a sloping ceiling or beneath a window, low profile designs around 70cm are the practical choice.

Winged headboards add width as well as height. A wing that projects 8cm on each side adds 16cm to the total footprint, which is enough to matter in a room where the bed only just fits. Check the external width on any winged design rather than assuming it matches the mattress size.

Getting the Delivery Right

Frames arrive flat packed and assemble in the bedroom, so the awkward item is always the mattress. A 180cm super king mattress cannot be folded and only compresses slightly, so the route into the room needs checking properly.

Measure the front door width, the narrowest point in the hall, the stair width, the ceiling height above the stairs, and the diagonal clearance at any turn. Bannister newel posts reduce a turn more than people expect, and a half landing under 90cm deep will usually defeat a super king mattress in one piece.

Clear the room before delivery day. Assembling a large frame needs floor space around the build area, and dismantling the old bed first avoids a bottleneck. If the old mattress is going, arrange its removal in advance, since a super king mattress is difficult to store temporarily anywhere in an average house.

Frequently Asked Questions

What size is a UK king bed in centimetres?

150cm wide by 200cm long. In imperial measurements that is 5ft by 6ft 6in.

Is a super king much bigger than a king?

It is 30cm wider at 180cm, with the same 200cm length. That is roughly an extra 15cm of width per sleeper.

Why do American king beds have different measurements?

The US uses its own standard, with a king at around 193cm by 203cm. It is wider and slightly longer than a UK king, so bedding and frames are not interchangeable.

What is an emperor bed size?

Emperor beds are usually around 200cm by 200cm, though sizes vary by maker. Check the specific mattress dimensions before buying bedding.

Do I need a bigger duvet for a king bed?

Yes. A king duvet is wider than a double, and using a double duvet on a king mattress leaves too little overhang on each side.