Backing and Binding Calculator

Backing & Binding Calculator

Enter your finished quilt top dimensions below to calculate how much fabric you need. It will automagically appear in the boxes at the bottom of the page.

Quilt top size

Backing options

Binding options

Backing fabric needed

yards
Backing size needed
Number of panels
Cut each panel

⚠ Quilt width exceeds fabric width. Check your fabric selection.

Binding fabric needed

yards
Quilt perimeter
Total strip length
Strips to cut
Strip width

Note: All yardage is rounded up to the nearest ⅛ yard. Backing uses 40″ usable width for standard 44″ WOF fabric (after removing selvages and allowing for shrinkage). Binding includes 12″ extra for diagonal joins and finishing. Always buy a little extra — fabric is never sorry to be left over!


Here is a method of creating a backing with the seam on the diagonal, invented by John Flynn. This diagonal backing method works best when the backing size needed is no more than about 1½ times the usable width of your fabric. In Step One, you cut a diagonal line through the length of fabric amount given by the calculator. Slide one side down until you get the width of the quilt top plus 8-1/2″ for the longarmer and a seam allowance. Sew along the diagonal. Trim as shown.

Step one shows a rectangle labeled Length and Width of Fabric with a diagonal dashed line. Step two, using the Backing and Binding Calculator, displays the rectangle cut along the diagonal with a rotary cutter, and Trim here labels by the cut edges.

Diagonal Backing Calculator

Enter the size of your quilt top. This calculator automatically adds 4″ to each side for longarm quilting.

Calculate

Enter your quilt top size, then click Calculate Backing.


BiographyPhoebe Moon (also known as Kris Driessen) brings warmth and creativity to every corner of the quilting world. A former quilt shop owner and passionate pattern designer, she’s spent years inspiring quilters of all skill levels through her clever designs, time-saving techniques, and hands-on teaching. Whether sharing beginner-friendly projects, guiding advanced quilting methods, or creating step-by-step tutorials, Phoebe loves helping others grow in their craft. Explore her collection of Printable PDF Quilt Patterns on Etsy —from mini quilts and table runners to full-size bed quilts—and discover the resources, inspiration, and community that make quilting such a joy.