Cushion cover fabric calculator
Pick your insert size and cover style, and get every cut piece, the fabric to buy, and piping if you want it.
Enter your numbers
How it is calculated
A cushion cover looks best slightly smaller than its insert, so the insert stays plump. Standard fit cuts the front at the insert size plus 1 in, which finishes at the insert size and gives an easy fit; snug fit cuts the front at exactly the insert size, finishing 1 in smaller for a plumper look. Both include 1/2 in seams.
Zip backs are cut as two pieces, each the front width by half the front height plus 1 in, joined around the zip. Envelope backs are two pieces, each the front width by half the insert size plus 5 in, which covers hems and a generous overlap. The tool lays the pieces across your fabric's usable width and totals the length to buy. Piping needs the cushion perimeter plus 4 in per cover, cut as continuous bias from a small square.
Worked example
Two 18 in zip covers in standard fit from 44 in quilting cotton: each cover needs a 19 in front and two 19 x 10 1/2 in back pieces. Two covers fit side by side across the width, so the total is 40 in of fabric: buy 1 1/8 yd. With piping, that is 152 in of covered cord, cut from an 18 in square, so add 1/2 yd of piping fabric.
Common questions
- How much fabric for an 18 inch cushion cover?
- One zip cover in standard fit needs a 19 in front and two 19 x 10 1/2 in backs. From 44 in fabric that is about 7/8 yd for one cover, and 1 1/8 yd covers two, since pieces sit side by side.
- What size should a cushion cover be compared to the insert?
- The finished cover should equal the insert size or run up to 1 in smaller. A cover larger than its insert always looks limp. This calculator's standard fit finishes at the insert size; snug finishes 1 in under.
- How much overlap does an envelope back need?
- About 4 in of overlap keeps the insert from peeking out, and each edge needs a hem. The two back pieces this tool cuts give roughly a 4 in overlap with 1 in double hems.
- How much piping cord do I need?
- The perimeter of the cushion plus about 4 in for joining, per cushion. An 18 in cushion needs 76 in. Cut the fabric that covers the cord on the bias so it curves smoothly at the corners.
Related tools
SewCalc results are careful estimates based on standard practice. Fabrics, brands and personal technique vary, so always confirm measurements against your own pattern or project before cutting.