Duvet cover size chart
Updated August 2026
Every dimension you need in one place: US mattress and cover sizes, the UK, EU and IKEA equivalents, the drop calculation that predicts overhang, and the fit rule that decides whether an insert sits flat or swims.
1. US mattress and cover sizes
Two different measurements get confused constantly. The mattress size is what you sleep on. The cover size is what the duvet cover and its insert measure. They are never the same number, and covers are cut generously so they can hang.
| Size | Mattress (in) | Duvet cover / insert (in) | Drop per side |
|---|---|---|---|
| Crib | 28 × 52 | Use a blanket, not a duvet | — |
| Twin | 38 × 75 | 68 × 90 | 15″ |
| Twin XL | 38 × 80 | 68 × 90 | 15″ |
| Daybed | 39 × 75 | 68 × 90 (twin) | 14.5″ |
| Full | 54 × 75 | 80 × 90 sold alone; 90 × 90 as Full/Queen | 13″ / 18″ |
| Queen | 60 × 80 | 90 × 92 | 15″ |
| King | 76 × 80 | 104 × 92 | 14″ |
| California King | 72 × 84 | 104 × 98 | 16″ |
| Oversized king | 76 × 80 | up to 120 × 120 | up to 22″ |
Two quirks worth memorizing. Twin and Twin XL usually share one cover size because the 5 inch mattress difference disappears into the overhang. And "Full/Queen" is a single 90 × 90 product sold for both beds, which is why a full-size buyer often ends up with 18 inches of drop per side. Size-specific detail lives on twin, twin XL, full, queen, king and California king pages.
2. UK, EU and IKEA conversions
European bedding is designed in centimeters, and the sizes were never derived from American mattress dimensions, so nothing maps cleanly. Inches below are converted at 1 cm = 0.3937 in.
| Name | Centimeters | Inches | Closest US cover |
|---|---|---|---|
| UK Single | 135 × 200 | 53.1 × 78.7 | Nothing — narrower and shorter than US twin |
| EU Single | 140 × 200 | 55.1 × 78.7 | Undersized twin |
| IKEA Twin | 150 × 200 | 59.1 × 78.7 | Undersized twin (68 × 90) |
| UK / EU Double | 200 × 200 | 78.7 × 78.7 | Undersized full |
| UK King | 225 × 220 | 88.6 × 86.6 | Near US queen width, 5″ shorter |
| IKEA Full/Queen | 240 × 220 | 94.5 × 86.6 | Wider than US queen, 5.4″ shorter |
| EU / IKEA King | 240 × 220 | 94.5 × 86.6 | Far narrower than US king (104 × 92) |
| UK Super King | 260 × 220 | 102.4 × 86.6 | Near US king width, 5.4″ shorter |
The pattern is consistent: European covers are square-ish and American covers are long. Every European size is shorter than its nearest US equivalent, which is the single most common source of cold feet and bunched inserts. IKEA is the case most US buyers actually hit, and it gets its own breakdown in IKEA duvet sizes vs. US bedding.
3. Worked example: the drop calculation
Drop is how far the cover hangs down each side. The formula has two steps:
Drop per side = (cover width − mattress width) ÷ 2, then subtract the mattress height to see what is left below the mattress.
Run it on a queen. The cover is 90 inches wide, the mattress is 60 inches wide:
(90 − 60) ÷ 2 = 30 ÷ 2 = 15 inches of drop per side.
Now account for mattress height. On a 14 inch mattress, 15 − 14 = 1 inch hanging below the top of a standard box spring — the cover just reaches the seam and stops. On a 10 inch mattress, 15 − 10 = 5 inches of visible hang, which is the classic look most bedding photography is shot with.
| Size | Cover width | Mattress width | Math | Drop per side |
|---|---|---|---|---|
| Twin | 68″ | 38″ | (68 − 38) ÷ 2 | 15″ |
| Full | 80″ | 54″ | (80 − 54) ÷ 2 | 13″ |
| Queen | 90″ | 60″ | (90 − 60) ÷ 2 | 15″ |
| King | 104″ | 76″ | (104 − 76) ÷ 2 | 14″ |
| Cal King | 104″ | 72″ | (104 − 72) ÷ 2 | 16″ |
Length works the same way but only at the foot, since the head end tucks under pillows: a Cal King cover at 98 inches over an 84 inch mattress leaves 98 − 84 = 14 inches at the foot.
4. The deep-mattress problem
Notice that king has the least drop of any standard size — 14 inches. Pillow-top and hybrid mattresses now routinely measure 15 to 18 inches tall. On a 16 inch king mattress: 14 − 16 = −2, meaning the cover stops 2 inches short of the bottom of the mattress and the fitted sheet shows all the way around. Add a mattress topper and the shortfall grows.
There are two fixes and both cost money. Buy oversized — 108 × 96 or larger, covered in oversized king bedding — or move up a size, using a Cal King cover on a king mattress to gain 2 inches per side. Measure your mattress with the topper on before deciding, not the number the manufacturer printed on the box.
5. Insert-to-cover fit rules
- Match the insert to the cover, never to the mattress. The cover is the constraint.
- 0 to 2 inches larger cover than insert in each dimension is the target. Equal is ideal; a slightly larger cover is fine.
- An insert more than 2 inches larger than the cover compresses at the edges, loses loft along the perimeter and strains the seams.
- An insert more than 3 inches smaller slides freely, pools at the foot and leaves a cold flap at the top.
- Allow for shrinkage. Unwashed cotton and linen lose 3–5% on the first hot wash — on a 92 inch length that is 3 to 4.5 inches. Buy garment-washed, or size up.
- Ties are not optional at these tolerances. Four minimum, eight on queen and larger.
Red flags
- A listing that gives only "Queen" with no inches. Queen covers range from 88 to 92 inches long across brands.
- Dimensions in centimeters on a US storefront. Almost always a European or IKEA-spec product.
- "Fits all mattress depths." No cover can, because drop is fixed by width.
- A comforter sold as king at 90 inches wide. That is a queen with a king label.
- Set photography on a low platform bed. The drop you see is not the drop you get on a 15 inch hybrid.
Where to go next
Every size broken out individually in the sizes hub, shortlists in best duvet covers, and more measurement guides in all guides.