Free Quilt Calculator

Eight essential calculators — fabric, binding, backing, borders & more

Quilt Backing Calculator

Calculate exactly how much fabric you need for your quilt backing. Enter your finished quilt dimensions, desired overhang, and your fabric's width to instantly get total yardage, the number of panels to sew together, and the batting size you'll need.

Backing & Batting

Calculates yardage for a pieced backing. Panels are sewn side-by-side to reach the required width. Default 4" overhang per side is standard for quilting frames; use 2–3" for hand quilting.

All calculations show the exact fabric needed based on your inputs — they do not include extra for cutting errors. Consider adding 5–10% to any yardage figure. Standard quilting cotton WOF is 44".

How It Works

  1. Add overhang to each side of your quilt. The default 4" per side (8" total per dimension) is standard for longarm quilting frames.
  2. Determine how many fabric panels are needed by dividing the required backing width by the usable fabric width (WOF minus 0.5" for trimming).
  3. Multiply the number of panels by the required backing length to get total fabric inches, then round up to the nearest ⅛ yard.

Frequently Asked Questions

How much overhang should I add to my quilt backing?
The standard for machine quilting on a longarm frame is 4 inches per side (8 inches total per dimension). For hand quilting or domestic machine quilting, 2–3 inches per side is sufficient.
What width of fabric should I use for quilt backing?
Standard quilting cotton is 44" wide, but wide-back fabrics are available in 108" width. Wide-back fabric saves seams — use this calculator with 108 in the fabric width field to see how much less you need.
Should I pre-wash my quilt backing fabric?
Most quilters pre-wash cotton backing fabric to prevent shrinkage after the quilt is completed. Pre-washing can reduce fabric length by 3–5%, so consider buying a little extra or use slightly larger dimensions in the calculator.
Does the calculator include seam allowances between panels?
The panel calculation subtracts 0.5" from the WOF for selvage trimming. Seam allowances between the panels themselves are accounted for because panels are added at full length — the extra overhang and the rounding up to ⅛ yard typically absorbs the seam loss.

Related Calculators

Binding CalculatorBorder CalculatorYardage CalculatorQuilt Size Chart