Show the formula and working
This duvet size converter helps people in the UK, Ireland and Europe match a duvet or duvet cover to the sizes sold in another country, and it also tells you how far the duvet will hang over the sides of your mattress. Choose your duvet, pick the country you are buying from and enter your mattress width: the tool names the closest UK, European or US duvet, the size gap in centimetres and inches, and the overhang on each side.
Quick answer: UK duvets are 135 x 200 cm (single), 200 x 200 cm (double), 225 x 220 cm (king) and 260 x 220 cm (super king). IKEA in Europe sells 150 x 200, 200 x 200, 240 x 220 and 260 x 220 cm. US full/queen duvets are about 229 cm square. A duvet size converter matches them.
What Is a Duvet Size Converter?
A duvet size converter is a tool that compares your duvet’s width and length with the standard duvet sizes of another country and names the closest one, so you can buy a duvet or cover that fits. The formula in plain words: each standard duvet scores its width gap plus half its length gap, and the lowest score wins. The overhang is the duvet width minus the mattress width, divided by 2.
The UK sizes come from the Marks and Spencer bedding size guide, with the emperor size from Woolroom. European sizes follow the IKEA guide to bedding sizes, as IKEA sells the same duvet sizes across much of Europe. The US has no single standard, so the tool uses one maker’s comforter sizes as the example and shows the range across other brands in the breakdown.
How Do You Use the Duvet Size Converter?
- Choose your duvet in Your duvet size, or choose Custom duvet size and enter the Custom duvet width and Custom duvet length from the label.
- Choose the country you are buying from in Convert to.
- Enter Your mattress width in centimetres, for example 137 for a UK double or 152 for a UK king or US queen.
- Read the closest duvet, the size difference and the overhang on each side of your mattress.
- Read the result and open “Show the formula and working” to see the score and overhang sums.
What Size Duvet Do I Need for a King Size Bed?
A UK king bed (152 cm wide) takes a king duvet of about 225 x 220 cm, which leaves roughly 37 cm hanging over each side. Many couples choose a super king duvet (260 x 220 cm) on a king bed instead, which gives about 54 cm each side and less tugging at night. In Europe, a 160 cm bed usually takes a 240 x 220 cm duvet, and in the US a queen bed takes a full/queen duvet of about 229 cm wide.
Are UK and US Duvet Sizes the Same?
No: US duvets are generally larger and squarer than UK duvets of the same name, and they are sold in combined sizes such as full/queen and king/California king. A US full/queen insert of about 90 x 90 in (229 x 229 cm) is wider than a UK king and longer than a UK super king. US sizes also vary by brand, from about 90 to 93 in wide for full/queen, so check the label in inches before buying a cover to go with it.
Will a European Duvet Cover Fit a UK Duvet?
A European cover only fits a UK duvet when both share the same size, which is true for the 200 x 200 cm double and the 260 x 220 cm super king. A UK single (135 x 200 cm) is 15 cm narrower than the IKEA 150 x 200 cm single, and a UK king (225 x 220 cm) is 15 cm narrower than the 240 x 220 cm European size. A cover that is too big lets the duvet bunch up inside, so buy the cover in the same system as the duvet.
How Much Should a Duvet Hang Over the Bed?
A UK duvet in the matching size hangs about 22 to 39 cm over each side of the mattress: a single gives 22 cm on a 91 cm bed, a double gives 32 cm on a 137 cm bed and a super king gives 39 cm on a 183 cm bed. Deeper mattresses and two sleepers both use up overhang, so going one size up is common. The converter warns you when the overhang drops below 15 cm each side.
UK, EU and US Duvet Size Chart
| Bed | UK duvet | EU duvet (IKEA) | US duvet (example brand) |
|---|---|---|---|
| Single or twin | Single, 135 x 200 cm | 150 x 200 cm | Twin, 64 x 90 in (163 x 229 cm) |
| Double or full | Double, 200 x 200 cm | 200 x 200 cm (140 cm beds) | Full/queen, 90 x 90 in (229 x 229 cm) |
| King or queen | King, 225 x 220 cm | 240 x 220 cm (160 cm beds) | Full/queen, 90 x 90 in (229 x 229 cm) |
| Super king or king | Super king, 260 x 220 cm | 260 x 220 cm (180 cm beds) | King, 106 x 90 in (269 x 229 cm) |
| Emperor | Emperor, 290 x 235 cm (varies) | No standard | No standard |
US brands differ: other makers list twin duvets up to 72 x 96 in, full/queen up to 93 x 96 in and king up to 107 x 98 in. Treat the US column as a guide and always read the label.
Worked Example: A UK King Duvet on a US Queen Bed
Example: after a move to the US, a UK king duvet (225 x 220 cm) needs a new cover. The American bed is a queen with a 152 cm mattress. Choose UK king (225 x 220 cm) in Your duvet size, United States and Canada in Convert to, and enter 152 in Your mattress width. The converter shows US full / queen, 229 x 229 cm, a difference of +4 cm in width and +9 cm in length, and an overhang of 38 cm each side: (229 minus 152) divided by 2. A full/queen cover will hold the duvet with a little room to spare.
Heavier duvets and bedding take longer to dry, so if you tumble dry, our electricity cost calculator shows what each load costs. For more household tools, see our home calculators.
Duvet Size Converter FAQs
What size is a double duvet in cm?
A UK double duvet is 200 x 200 cm, and IKEA sells the same 200 x 200 cm size in Europe for 140 cm beds. Double duvet covers in the UK are usually 200 x 200 cm too, give or take 2 cm depending on the brand.
What is a US queen duvet in UK size?
A US full/queen duvet of about 229 x 229 cm (90 x 90 in) sits between a UK king (225 x 220 cm) and a UK super king (260 x 220 cm). It is closest to a UK king in width but about 9 cm longer, so a UK king cover will be a snug fit.
Can I put a super king duvet on a king bed?
Yes. A super king duvet (260 x 220 cm) on a 152 cm UK king bed hangs about 54 cm over each side, against 37 cm for a king duvet. Many couples prefer it because there is enough width for both sleepers to stay covered.
What size duvet fits a European 140 x 200 cm bed?
IKEA pairs a 140 x 200 cm bed with a 200 x 200 cm duvet, which is the same as a UK double. That leaves about 30 cm over each side. For more cover, IKEA also lists the 240 x 220 cm duvet for 140 cm beds.
Is a duvet cover the same size as the duvet?
Yes, a duvet cover is made to the same nominal size as the duvet it fits, within a few centimetres. Marks and Spencer, for example, lists a 200 x 200 cm double duvet and a 198 x 198 cm double cover. Always buy the cover in the same named size and country as the duvet.
Does duvet tog change the size?
No. Tog measures how warm a duvet is, not how big it is, so a 4.5 tog and a 13.5 tog double are both 200 x 200 cm. Thicker, higher tog duvets can feel a little tighter inside a cover, but they use the same cover size.
Checked October 2026. Sources: Marks and Spencer bedding size guide, Woolroom size guide (emperor duvet), IKEA guide to bedding sizes, Brooklinen comforter dimensions, Parachute duvet insert size guide, Casper bedding sizes.