UK vs EU vs US Bed Sizes Compared: Why a King Is Not a King Everywhere

A king size bed in the UK, a king size bed in the United States and the nearest European equivalent are three different beds. They differ in both width and length, they take different bedding, and none of the three mattresses will fit correctly in another’s frame. The word king describes a position in a national range, not a dimension.

This matters more than it used to because furniture, bedding and mattresses are now bought across borders routinely. The most frequent problem we see is not someone buying the wrong bed. It is someone buying the right bed and then finding that fitted sheets bought elsewhere will not sit properly on the mattress, because the depth and the dimensions belong to a different system.

Key findings at a glance

• UK bed sizes are defined in imperial derived dimensions expressed in feet and inches, then converted to centimetres, while continental European sizes are set in round metric numbers.
• A UK king size mattress measures 150cm by 200cm (5ft by 6ft 6in), which is wider and shorter than a US king.
• A US king is 193cm by 203cm (76in by 80in), closer in width to a UK super king, and a US queen at 152cm by 203cm is almost the width of a UK king but longer.
• Common continental European double sizes run in round metric widths such as 140cm, 160cm and 180cm, usually at 200cm long.
• Length is the difference people notice least when ordering and most when sleeping, since a 200cm UK mattress is shorter than the 203cm standard common in the United States.
• Bedding is the practical failure point, because fitted sheets are cut to national mattress dimensions and to assumed mattress depths.

Why the three systems diverged

British bed sizes grew out of imperial measurement. A single is 3ft wide, a double 4ft 6in, a king 5ft and a super king 6ft. The metric figures published today are conversions of those imperial widths, which is why they land on numbers such as 135cm and 150cm rather than on round hundreds.

Continental Europe standardised metrically and chose round numbers, so widths of 140cm, 160cm and 180cm dominate, typically at 200cm long. There is no continental equivalent to the UK’s 135cm double, which is one of the more awkward gaps when buying bedding abroad.

The United States developed its own range in inches with a different priority: length. American standard mattresses are commonly 80in long, which converts to roughly 203cm. That extra length relative to the UK standard is consistent across the larger US sizes and is the difference most likely to be overlooked when comparing on width alone.

None of these systems is superior. They are simply three independent traditions that were never reconciled, and the naming overlap between them is coincidental rather than meaningful.

The sizes that cause the most confusion

The UK small double, at 120cm wide, has no direct counterpart in either of the other systems. It exists because British bedrooms frequently cannot take a full 135cm double alongside a wardrobe, and it is one of the most useful sizes in the UK range for that reason. Anyone shopping for it internationally will struggle, and anyone shopping for bedding for it should buy from a UK supplier.

The UK double at 135cm is narrower than the 140cm continental European equivalent and considerably narrower than a US queen. Two adults sharing a UK double have less width each than most people assume, and it is the size that most often prompts an upgrade.

The word king causes the most trouble of all. A UK king at 150cm is narrower than a US king at 193cm by a substantial margin. A UK super king at 180cm by 200cm is closer in width to the US king but still shorter. If you have slept in a king bed in an American hotel and want the same at home, the UK super king is the size to look at, not the UK king. Our super king size beds UK category is where that comparison usually resolves.

Frame size is not mattress size

Every dimension discussed so far is a mattress dimension. The bed frame is larger, and by a variable amount depending on the design. A slim metal frame may add only a few centimetres on each side. An upholstered frame with a deep surround, or a bed with a substantial footboard, can add considerably more in both directions.

This is the measurement people forget when planning a room. A 150cm mattress in a heavily upholstered frame can occupy a footprint approaching 170cm wide once the surround is included, and that difference decides whether a bedside cabinet still fits beside it. Always take the external frame dimensions from the product specification rather than calculating from the mattress size, and check the headboard height against any window sill behind the bed.

Storage beds add a further consideration: an ottoman or lifting base needs clearance above to open, and a divan with side drawers needs clearance beside it for the drawer to pull out. We see both discovered after delivery more often than before it. Anyone considering lifting storage should check the ceiling clearance as well as the floor plan, which applies across our ottoman beds UK range.

Fitting a bed into a real UK bedroom

Room planning for beds comes down to circulation. Allow at least 60cm to 70cm of clear floor along each side you need to walk down, and the same at the foot if there is a route past it. In a room where only one side is used for access, the bed can sit against a wall, but making a bed pushed into a corner is genuinely difficult and worth considering before committing.

Wardrobe and door swings are the next constraint. A hinged wardrobe door needs its full arc clear of the bed, which frequently determines bed position more than the window does. Sliding wardrobe doors remove that problem and are often the reason a larger bed becomes possible in a small room.

The Nationally Described Space Standard sets minimum internal floor areas and minimum bedroom widths for new homes in England, and those minimums explain why the small double and the UK double remain the most practical sizes in much of the newer housing stock. Upgrading to a king in a room built to a minimum width tends to work only where the wardrobe moves elsewhere.

Access is the final check, and the one that causes failed deliveries. Measure the narrowest point on the route in, including stair turns and landing width. Bed frames that ship in parts pass where a one piece frame will not, and a rolled or vacuum packed mattress passes where a traditional sprung mattress cannot. Frames within our double fabric beds UK range are supplied in parts for exactly this reason.

Standard mattress sizes across the three systems

The table below sets out standard mattress dimensions in each system. These are published standard sizes rather than statistical findings, and individual manufacturers may vary slightly.

What this means for UK homes

Buy the mattress and the bedding within the same national system. This is the most reliable rule in the whole subject. A UK king fitted sheet will not sit correctly on a US queen mattress even though the widths are within a few centimetres, because the length differs by several.

Check mattress depth as well as size. Fitted sheets specify a maximum depth, and deep pocket sprung mattresses with a topper routinely exceed what a standard sheet will accommodate. A sheet that keeps pulling off a corner is almost always a depth problem rather than a size problem.

Prioritise length for taller sleepers. A UK mattress at 190cm or 200cm is shorter than the American standard, and for anyone over about six feet the extra length of a UK king or super king at 200cm is more valuable than additional width.

Measure the frame, not the mattress, when planning the room. Then mark the full external footprint on the floor with tape and check that you can still open the wardrobe, pass the foot of the bed and fit a bedside cabinet either side.

Finally, if you are importing a bed frame or bringing one from abroad, accept that you will be buying mattresses and bedding in that system indefinitely. That is usually the decisive consideration, and it is better faced before the frame arrives.

Methodology

This 2026 comparison was compiled by our editorial team as a UK furniture retailer, using published standard mattress dimensions for the United Kingdom, continental Europe and the United States, standard bedroom circulation and clearance requirements, and UK housing context where a named public source genuinely applies, including the Nationally Described Space Standard for new homes in England. Dimensions are given as standard specifications and individual manufacturers may vary. The report contains no proprietary sales data and no survey fieldwork.

Citing this report

Media and websites are welcome to cite this 2026 comparison with credit to Furniture in Fashion as the publisher and a link back to this report. It sets out published standard bed sizes across three systems and does not present market measurement.

Frequently asked questions

Is a UK king the same as a US king?

No. A UK king measures 150cm by 200cm while a US king measures 193cm by 203cm, so the American bed is substantially wider and slightly longer. A UK super king at 180cm by 200cm is the closer comparison.

What is the European equivalent of a UK double?

The nearest is the continental 140cm by 200cm double, which is 5cm wider and 10cm longer than the UK double at 135cm by 190cm. There is no exact match, so bedding should be bought in the same system as the mattress.

Will US bedding fit a UK mattress?

Generally not. Even where widths appear close, the lengths differ, and fitted sheets are cut to national dimensions and assumed mattress depths. Buy bedding sized for the system your mattress belongs to.

What size bed fits a small UK bedroom?

A small double at 120cm wide is the size that most often solves the problem, since it gives two people more width than a single while leaving room for a wardrobe and a walking route. Allow 60cm to 70cm of clear floor along each access side.

Do I need to measure the frame as well as the mattress?

Yes. Upholstered and surround style frames can add a significant amount to the external footprint on every side. Always plan a room from the frame dimensions in the product specification, not from the mattress size.