Pillow shams are decorative covers for pillows, rather than covers you'd use to protect the pillow or to sleep on. Therefore, you can choose almost any fabric for a pillow sham and you can embellish it with piping, fringe, appliqué, needlepoint, embroidery, ribbon, buttons and an array of other creative additions. Many pillow shams have a flange, or a border of extra fabric around the perimeter. Figuring out how much yardage you need to make a pillow sham is easy—just measure and add.
Measure the Length of the Pillow
Measure the pillow's length. Double that measurement. Add 6 inches for the overlap at the back through which you'll insert the pillow. Add 1 inch for the fold over the hems at the ends of the fabric. Now decide how wide you want the flange to be. Double that measurement, then add all the measurements together. For example, to make pillow sham with a flange 4 inches wide for a pillow 15 inches long, your measurements will be 30 + 6 + 1 + 8 = 45. The length of the piece of fabric to make the pillow sham is 45 inches.
Measure the Width of the Pillow
Measure the pillow's width. Add 8 inches for the 4-inch flange. Add 1 1/4 inches for the seam allowance (the distance between the edge of the fabric and the seam you'll sew). Assuming your pillow is 12 inches wide, your measurements will be 12 + 8 + 1 1/4 = 21 1/4 inches. To make a pillow sham with a 4-inch flange for a pillow 15 inches long and 12 inches wide, you need a piece of fabric 45 inches long by 21 1/4 inches wide.
Non-Patterned Fabric More Than 45 Inches Wide
Assuming your fabric is more than 45 inches wide--and assuming it doesn't have a pattern that requires you to cut from the length of the fabric rather than the width--you can plan to cut the fabric for the pillow sham across the width. In the above example you'd need a piece of fabric more than 45 inches wide and 21 1/4 inches long. Divide 21 1/4 by 36 (the number of inches in a yard). The result is 0.59, or approximately 3/5 yard of fabric. Buy ¾ yard to be on the safe side in case the fabric isn't cut exactly square.
Patterned Fabric More Than 45 Inches Wide
If the pattern requires that you cut the pillow sham out from a length of fabric rather than a width, you'll need 45 inches of 45-plus-inch fabric. Divide 45 by 36. The result is 1.25 or 1 1/4 yards. You might want to buy 1 1/2 yards of fabric. This layout requires buying about twice as much fabric as the first layout. The good news is that you can lay out pillow shams for two, 12-by-15-inch pillows side-by-side on 1 1/2 yards of fabric.