UK Bed Sizes Explained: What Duvet, Sheet and Pillowcases You Actually Need

Bed sizes in the UK are named, not measured, which is why so many people end up with a duvet that hangs off one side and a fitted sheet that pings off a corner at 3am. This guide gives you the actual numbers for each size, and answers the two questions that cause the most returns: what depth of fitted sheet you need, and which pillowcase size to buy.

The UK bed sizes, in cm and feet

These are the mattress widths the names refer to:

Bed size	Mattress width	Duvet you need
Single	3 ft (90 cm)	135 x 200 cm
Small Double (three-quarter)	4 ft (120 cm)	200 x 200 cm
Double	4'6" (135 cm)	200 x 200 cm
King	5 ft (150 cm)	230 x 220 cm
Super King	6 ft (180 cm)	260 x 220 cm

Notice that the duvet is always considerably wider than the mattress. That difference is the drop — the part that hangs over the sides and stops your partner stealing it. A Double duvet at 200 cm on a 135 cm mattress gives roughly 32 cm of drop each side.

The small double, or three-quarter bed

A Small Double is 4 ft (120 cm) wide and 190 cm long — 15 cm narrower than a Double, the same length. It is the size most often found in student halls, box rooms and older houses, and it is the one the big four names leave out. There is no separate duvet size for it: a Small Double takes the same 200 × 200 cm duvet as a Double, which simply gives you a little more drop each side. For the sheet, we do not cut a dedicated 120 cm fitted sheet; a Double fitted sheet (135 cm) will go on with roughly 7 cm of slack each side and tuck under, which is what most small-double owners do. If you are dressing a halls bed, check whether it is a 3 ft Single or a 4 ft Small Double before you order — the two are often both described as "a single bed".

The King and Super King trap

King and Super King duvets are both 220 cm long, but 230 cm and 260 cm wide respectively. If you upsize your bed from King to Super King and keep the old duvet, the length still fits — so it feels almost right — while you lose 15 cm of drop on each side. It is the most common reason people tell us their new bed "feels colder". If you are upsizing, check the size on the duvet insert itself before you order covers to go over it.

Fitted sheets: width is easy, depth is not

The width of a fitted sheet is decided for you by the bed size. Depth is the part worth thinking about, and it is where most sizing mistakes actually happen.

Mattresses have got deeper over the last twenty years. A traditional sprung mattress might be 20 cm; a modern pocket-sprung or memory-foam mattress with a pillow top can be 30 cm or more, and that is before you add a topper. A fitted sheet cut for a shallow mattress will technically go on a deep one, but it will sit under tension and work its way off a corner during the night.

Our standard fitted sheets are cut for mattresses up to 35 cm — around 14 inches — deep. That covers the large majority of UK mattresses, pillow-tops included. From 15 inches upwards we tailor a deeper skirt, which you can choose when you build your set. Every size is cut in all four fabrics: Cloud Cotton, Silky Cotton, Linen and Plain Cotton.

Measure before you buy. Put a tape measure vertically against the side of the mattress, from the base to the top surface. Include a topper if you use one permanently — it is part of the depth as far as the sheet is concerned. Do not measure the bed frame.

If your measurement comes in over 35 cm, take the deeper option. There is no penalty for going deeper than you need: the extra fabric simply tucks further under the mattress. A sheet cut shallower than your mattress, on the other hand, will never stay put.

Pillowcases: Standard or King Size

Two pillowcase sizes cover almost every UK bed:

• Standard — the usual rectangular pillow, right for Single, Double and most King beds.
• King Size — longer, and the natural choice on a Super King, where two standard pillows leave a visible gap in the middle of a 180 cm headboard.

Both sizes come in every fabric we offer — Cloud Cotton, Silky Cotton, Linen and Plain Cotton — and sold in pairs.

This is aesthetic as much as practical. Two standard pillows on a Super King look marooned; two king-size pillows fill the width properly. If you sleep with four pillows, the usual arrangement is two king-size at the back and two standard in front — and a pillow insert in each, sized to the case rather than the other way round.

How many pillowcases come in a set

Our bedding sets include two pillowcases as standard, except Single sets, which include one. You can add a second pair if you sleep with four, or buy the duvet cover and fitted sheet separately if you already own pillowcases you like.

A quick checklist before you order

1. Confirm your bed size by measuring the mattress width, not the frame.
2. Measure mattress depth vertically, including any permanent topper — under 35 cm takes the standard sheet.
3. Choose your duvet size from the table above — match the bed, not the duvet you already own.
4. Pick Standard pillowcases, or King Size if you are dressing a Super King.

If you would rather see it than calculate it, you can build a complete set and pick the size once — the sheet, duvet cover and pillowcases all follow from it, so the pieces cannot end up mismatched.

Questions people ask about UK bed sizes

What size duvet do I need for a double bed?

A Double bed is 135 × 190 cm and takes a 200 × 200 cm duvet. That is 65 cm wider than the mattress, which gives roughly 32 cm of drop each side.

What size is a small double bed in the UK?

A Small Double, also called a three-quarter bed, is 120 × 190 cm — 4 ft wide. It takes the same 200 × 200 cm duvet as a Double; there is no separate small-double duvet size.

What size is a king duvet in the UK?

A UK King duvet is 230 × 220 cm, for a 150 × 200 cm mattress. A Super King duvet is 260 × 220 cm, for a 180 × 200 cm mattress.

Is a UK king bed 5ft?

Yes. A UK King mattress is 5 ft (150 cm) wide and 200 cm long. A Super King is 6 ft (180 cm) wide and the same 200 cm long, so the two differ in width only.

Will a king duvet fit a super king bed?

It will cover the mattress but it will not hang properly. A 230 cm duvet on a 180 cm mattress leaves about 25 cm of drop each side instead of 40 cm, so it slides off one edge during the night.

How deep do fitted sheets need to be?

Our fitted sheets are cut for mattresses up to 35 cm deep as standard, which covers most UK mattresses plus a topper. Measure from the top surface of the mattress to the bottom seam before ordering.

What size pillowcases do UK pillows take?

A Standard pillowcase is 50 × 75 cm and a King Size pillowcase is 50 × 90 cm. Both are sold in pairs in all four fabrics. A body pillowcase is 45 × 150 cm and is Plain Cotton only.

If you are dressing a six-foot bed, the super king bedding page lists every super king measurement and the live price of each configuration.