Measure your headboard's width, height and depth to calculate the amount of fabric needed to cover the headboard using 1/2" seams. (If your headboard can be easily removed, then alternatively put the headboard on top of your fabric and trace a pattern around it that includes seam allowances.) Be generous with measurements and round up to be safe, it's better to add more inches and trim it down later. Here was our formula: the top strip of the headboard measured 3" x 67" and will have 1/2" seams on every side, so the final piece measured 4-1/2" x 69". The front/back measured 35" tall x 67" wide, we added 4" to the height to account for the bottom hem plus the 1/2" seam allowance resulting in two pieces at 39" x 69". The tapered sides were trickier because they are 3" wide at the top and 8" wide at the bottom. So we calculated two slanted fabric pieces at 4-1/2" wide at the top, 10" wide at the bottom, and 39" tall.