Quilt Backing Calculator
Calculate how much backing fabric to buy, how many panels you need, and how to cut them. Compare vertical and horizontal seam layouts automatically.
Backing Yardage Calculator
Enter the finished quilt-top size and the usable width of your backing fabric.
Your Results
Vertical Layout
Horizontal Layout
How the Quilt Backing Calculator Works
Backing needs to extend beyond the quilt top on every side. The calculator first adds your chosen allowance, then checks how many usable fabric-width panels are needed in both seam directions.
Worked Example: 60 × 80 Inch Quilt
With 4 inches of extra backing on each side, the required backing is 68 × 88 inches. With 42-inch usable fabric, two vertical panels require 176 linear inches, or about 4.89 yards, so the practical purchase amount is 5 yards. A horizontal layout needs three 68-inch panels and therefore more fabric.
Standard Fabric vs. 108-Inch Wide Backing
Standard quilting cotton often has about 40–44 inches of usable width and requires piecing for larger quilts. A 108-inch wide-back fabric can cover many quilts with one panel and eliminate backing seams. Enter the actual usable width of the fabric you plan to buy.
Vertical vs. Horizontal Backing Seams
Vertical seams use panels cut to the backing length and joined side by side. Horizontal seams use panels cut to the backing width and stacked top to bottom. Neither orientation is always best, so Auto compares both and recommends the layout that uses less linear fabric.
How Much Extra Backing Should You Add?
Many longarm workflows request extra backing around all four sides, but requirements vary by quilter and machine. Use the allowance requested by the person quilting the project rather than treating one number as universal.
Frequently Asked Questions
How do I calculate quilt backing yardage?
Add your desired extra backing to all four sides, calculate how many fabric-width panels are required, multiply the panel count by each panel's cut length, then convert the total linear length to yards or meters.
How much backing do I need for a 60 × 80 quilt?
With 4 inches extra per side and 42-inch usable fabric, the backing needs to be 68 × 88 inches. Two vertical panels require about 4.89 yards, which rounds up to a practical 5-yard purchase.
Should quilt backing seams run vertically or horizontally?
Either can work. Compare both orientations and choose the one that suits your fabric direction, quilting setup and yardage needs.
Can I use 108-inch wide backing?
Yes. Wide-back fabric can eliminate seams on many quilts. Enter 108 inches, or the actual usable width, in the fabric-width field.
Should I include selvages in fabric width?
Use the width you actually expect to sew into the backing. If you will trim selvages, enter the remaining usable width.
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