Quilt Fabric Yardage Converter

Estimating quilt fabric yardage requires knowing the finished quilt size, block size, and how many different fabrics you plan to use.

Standard quilt sizes (finished dimensions):

Quilting fabric standard width: Most quilting cotton fabric is 44-45 inches (112-114 cm) wide on the bolt. After removing selvage edges, the usable width is approximately 42 inches (107 cm).

How to estimate yardage for patchwork tops:

1. Work out the area of the quilt: Width x Length
2. Divide by the usable fabric width (42 inches). That gives the linear inches of fabric you need, not a number of strips
3. Divide by 36 for yards, then add 10-15% for waste from cutting, squaring up, and seam allowances

Step 2 is where estimates go wrong most often. A patchwork top is cut into pieces, so what matters is total area, and the fabric can be used right across its width. Counting whole 42-inch widths instead is the backing calculation, and applying it to a top overstates a twin by nearly half.

Quick yardage estimates by quilt size (single fabric for entire top):

Top figures include the 15% waste allowance; backing assumes 4 inches of overhang on every side. Everything is rounded up to the next quarter yard, since that is how a shop cuts it.

Backing fabric note: Quilts wider than 42 inches need pieced backing, two or more full widths sewn together, which is why backing eats more fabric than the top even though it is one flat piece. The seam does not have to run the way you assume. On a full-size quilt, running the seam across the quilt instead of down it saves nearly a yard, because the widths then have to span 98 inches rather than 88 and you need the same three either way. The calculator checks both directions and reports the cheaper one.

How much overhang? Longarm quilters generally insist on 4 inches of backing past the quilt top on all sides, and many will refuse a quilt with less. If you are quilting it yourself on a domestic machine, 2 inches is usually enough and saves real money on a big quilt.

Binding calculation:

• Binding strips go around the entire perimeter of the quilt.
• Perimeter = 2 x (Width + Length) + 10 inches (for joining strips and corners).
• Standard binding is cut 2.5 inches wide.
• Yards of binding fabric = (Perimeter / 42 inches per strip) x 2.5 inches / 36 inches per yard.

Practical tips:

• Always buy 10-15% more fabric than calculated to account for shrinkage, cutting errors, and squaring up.
• Pre-wash all fabrics before cutting to prevent uneven shrinkage in the finished quilt.
• Fat quarters (18 x 22 inches / 46 x 56 cm) are popular for variety in patchwork but less efficient for large pieces.
• When using multiple fabrics, divide the total yardage among the number of fabrics, then add extra for each.