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Duvet Cover Calculator — Fabric Yardage
Calculate fabric for duvet covers in standard UK sizes.
How We Calculate This
A duvet cover needs two pieces (front and back) slightly larger than the duvet. If the fabric is narrower than the cover, each side is made from one full-width centre panel plus two narrow side strips, seamed together — the centre-panel layout used in UK make-your-own tutorials.
The formula
Cut width = Duvet width + (Seam allowance × 2)
Cut length = Duvet length + (Seam allowance × 2) + Flap/finishing allowance
Usable width = Fabric width − Selvedge trim
If Cut width ≤ Usable width: 1 panel per side, so 2 full lengths (front + back).
If wider: 1 centre panel per side + side strips. The four narrow side strips (two per side) are ganged into the fewest extra full-width lengths that fit, instead of each panel taking a whole fabric width.
Total fabric = Number of cut lengths × Cut length
Frequently Asked Questions
Single: 135x200cm. Double: 200x200cm. King: 230x220cm (some retailers list 225x220cm). Super King: 260x220cm. These are the standard cover/duvet sizes; the fabric is cut with seam allowance and a finishing allowance added.
Wider fabric (150cm or extra-wide 228cm sheeting) reduces or eliminates the need for seaming panels. A 150cm-wide fabric works without seaming for a single cover. For double and larger on 150cm fabric the calculator uses the centre-panel layout — one full-width panel per side plus two narrow side strips — or you can use 228cm-wide sheeting to avoid seams entirely.
Common options are an internal (housewife) flap, press studs, buttons, or a zip. The calculator adds a small finishing/hem allowance at the opening (5cm by default). For a proper self-closing internal flap, increase the Flap Allowance in advanced options to about 15-20cm so the flap can tuck over the duvet. Buttons are traditional; press studs are quick.
Yes, always pre-wash cotton fabric for duvet covers. Cotton can shrink 3-5% in the first wash. Pre-washing also removes sizing and ensures the fabric is soft from the start.
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Last updated: February 2026
All calculations are estimates. Always verify quantities before cutting or purchasing fabric.