Formula
Straight-grain binding is the perimeter, plus a tail, cut into width-of-fabric strips.
length = 2 × (width + length) + extra
strips = ceil(length ÷ fabric width)
yards = strips × strip width ÷ 36
Yardage then rounds up to the next eighth of a yard, the way a shop cuts. A 2½ inch strip is the usual double-fold.
Worked examples
60 × 80, 2½ inch strips, 42 inch fabric, 12 inch tail. Perimeter = 280 in. Length = 292 in. That is 7 strips. Seven times 2.5 is 17.5 inches of fabric, 0.486 yards, which cuts as ½ yard.
Queen 90 × 108, same strip. Perimeter = 396 in. With the 12 inch tail that is 408 inches, 10 strips, 25 inches of cloth, 0.694 yards, which cuts as ¾ yard.
Reference
2½ inch strips, 42 inch usable width, 12 extra inches. Common finished sizes, not a bedding standard.
| Quilt | Perimeter | Strips | Buy |
|---|---|---|---|
| Throw 50×65 | 230 in | 6 | 1/2 yd |
| Twin 63×87 | 300 in | 8 | 5/8 yd |
| Full 78×87 | 330 in | 9 | 5/8 yd |
| Queen 90×108 | 396 in | 10 | 3/4 yd |
| King 108×108 | 432 in | 11 | 7/8 yd |
Questions
How do I calculate quilt binding yardage?
Add the four sides, then add a tail for the joins and the corners. Divide that length by the width of the fabric to get the number of strips, round up, and multiply by the cut width of the strip. Divide by 36 and round up to the next eighth of a yard.
What strip width is double-fold binding?
A 2½ inch straight-grain strip is the usual double-fold binding. It finishes near ⅜ inch. A wider strip finishes wider. This calculator is the cut strip, not the finished width.
Should I add extra for the join?
Yes. The default adds 12 inches to the perimeter for the diagonal joins, the corners, and a tail to finish the last join. A pieced binding with many seams can use a little more. Type it in.
Does this cut bias binding?
No. Bias is cut on the diagonal and the yield is lower. These strips are straight grain, cut across the width of the fabric, which is the ordinary binding for a straight quilt edge.
Sources
- Straight-grain double-fold binding: length = 2 × (width + length) + join allowance. Strips = ceil(length ÷ width of fabric).