What Size Is the Bed?

The direct answer

To find out what size a bed is, measure the mattress rather than the frame: measure the width across the head end and the length down one side, then compare those figures with the UK sizes. A single is 90cm by 190cm, a small double is 120cm by 190cm, a double is 135cm by 190cm, a king is 150cm by 200cm and a super king is 180cm by 200cm.

If your measurement falls a centimetre or two either side of one of those numbers, that is normal. Mattress covers stretch slightly with use and quilting adds a little to the edges, so treat the nearest standard size as the answer.

How to measure an existing bed properly

Strip the bedding off first, because a duvet and fitted sheet can hide a few centimetres. Lay a tape measure flat across the mattress from one side seam to the other, keeping it level rather than following the curve of the quilting. Do the same lengthways from the head seam to the foot seam.

Measure the depth separately, from the base of the mattress to the highest point of the surface, ignoring the loft of the quilting when it is compressed. Depth is what you need for fitted sheets and for judging how the mattress sits inside a frame, and it is the figure most people forget to take.

Finally measure the frame externally: outside edge to outside edge across the widest point, and from the back of the headboard to the front face of the footboard. Those are the numbers that decide whether the bed fits the room.

The UK size chart in full

Single: 90cm by 190cm. Long single: 90cm by 200cm. Small double: 120cm by 190cm. Double: 135cm by 190cm. King: 150cm by 200cm. Super king: 180cm by 200cm. Children’s cot bed sizes sit below all of these and vary by manufacturer, commonly around 70cm by 140cm.

Two things stand out in that list. Length is 190cm for everything up to a double and 200cm from king upwards, so extra length only comes with extra width unless you choose a long single. And the jumps in width are uneven: 30cm from single to small double, 15cm from small double to double, 15cm again to king, then 30cm to super king.

Why frame size and mattress size differ

A frame has to hold the mattress, so it always measures more. A metal frame may add only 5cm of width in total, while a deeply upholstered frame can add 15cm or more. Length grows for the same reasons, plus any footboard.

This is why two beds described as double can occupy noticeably different amounts of floor. When comparing options, look at the assembled dimensions on the product page rather than the size name. We list those figures for every bed in our modern beds UK sale range so the comparison is straightforward.

Identifying an unlabelled bed

Second hand and inherited beds often have no label left. Width usually settles the question on its own, since the standard widths are far enough apart to be unambiguous. If the mattress measures around 137cm, it is a double. Around 122cm, it is a small double. Around 152cm, it is a king.

Foreign sizes are the exception that causes confusion. A continental European double is commonly 140cm by 200cm and a European king is 160cm by 200cm, both longer than the UK equivalents. An American queen is roughly 152cm by 203cm, which is close to a UK king in width but longer. If your measurements land on those figures, UK bedding will not fit correctly.

Choosing the right size for the room

Once you know the sizes, the room decides which one to use. Mark the frame footprint on the floor with masking tape and live with it for a day. Check that the door still opens fully, that you can reach the wardrobe and that a radiator is not blocked, since a bed pushed against a radiator wastes the heat and can dry the mattress edge.

Allow 60cm of clear floor on any side you use for access and 50cm at the foot. If those margins mean the bed you want does not work, the answer is usually to drop one size rather than to accept a room you have to shuffle through sideways. In small rooms our small double fabric beds UK sale range is often the size that solves the problem, giving more width than a single without the footprint of a full double.

Matching bedding to the size you measured

UK bedding follows the mattress, not the frame. A single duvet is around 135cm by 200cm, a double is 200cm by 200cm, a king is 225cm by 220cm and a super king is 260cm by 220cm. Fitted sheets are cut to the mattress size, with the skirt depth doing the work of accommodating thickness.

If your mattress is deeper than about 27cm, look for a fitted sheet described as deep or extra deep. This is the most common reason sheets come loose at the corners overnight, and it has nothing to do with the sheet being the wrong bed size.

When the mattress and frame do not match

Occasionally a bed arrives with a mattress that is not quite right for the frame, usually because they were bought separately or years apart. A mattress that is too small leaves a gap at the sides, which allows bedding to tuck down and the mattress to slide. A mattress that is too large will ride up the rails and wear at the corners.

Neither situation is worth living with, since both shorten the life of the mattress. Replacing the mattress is the simpler fix in most cases, and our mattresses UK sale listings show width, length and depth together so you can match all three figures at once.

Practical notes for UK homes

Older UK houses were built before modern bed sizes settled, so bedrooms often have awkward features: a chimney breast that narrows the useful wall, a boxed in stair bulkhead, or a window sill sitting at 80cm. Measure at floor level and at headboard height, because the two can differ.

Loft conversions add a further complication. Where the ceiling slopes, the usable width at mattress height may be less than the floor width, so a bed pushed under the slope needs a low headboard or none at all. In that situation the frame length matters even more, since you may only have one viable orientation.

If you are furnishing a whole room, matching the bed to storage in the same finish keeps a small space looking deliberate rather than assembled piece by piece. You can see the full bedroom range alongside our other home collections at Furniture in Fashion, and we offer free delivery to most UK mainland postcodes.

When the measurement does not match any standard size

Older beds and imported frames sometimes measure between the standard sizes. A mattress at 137cm or 138cm wide, for example, is likely an older double made before sizing settled, and modern double bedding will usually still fit because bedding is cut with overhang. A mattress several centimetres away from any standard figure is a different matter and may need bedding a size up, accepting the extra drape.

Continental and American sizes are the other common source of confusion. A European double is often 140cm wide, and an American queen is 152cm by 203cm, which is close to a UK king without matching it. If your measurement lands on one of those figures, buy bedding to that standard rather than trying to force a UK size onto it.

Recording the measurements you take

Once you have measured, write the figures down somewhere you will find them again. Note the mattress width and length, the mattress depth, the overall frame width and length, and the headboard height. Those five numbers answer almost every question that comes up later, from replacing a mattress to deciding whether a new bedside cabinet will fit.

Add the room measurements alongside them, including the wall length where the bed sits and the clearance on each side. If the room has a radiator, a chimney breast or a door that swings inward, note those positions too. A short list like this turns a future purchase into a quick check rather than a repeat of the whole exercise.

Frequently asked questions

Should I measure the mattress or the frame?

Both. The mattress tells you the bed size for bedding and replacement mattresses. The frame tells you whether the bed fits the room.

My mattress measures 137cm wide. What size is it?

That is a standard UK double. Small variations of a centimetre or two above the stated 135cm are normal once the cover and quilting are accounted for.

How can I tell a UK king from a European king?

A UK king is 150cm wide and a European king is 160cm wide. Both are 200cm long, so width is the deciding measurement.

Does mattress depth change the bed size?

No. Depth affects fitted sheets and the finished height of the bed, but the size name is determined by width and length only.

What is the most common bed size in UK homes?

The standard double at 135cm by 190cm is the most widely used, since it suits the majority of UK main and second bedrooms.