Browser-local cut planning
Quilt backing calculator
Enter your quilt-top size, chosen extra backing per side, and usable fabric width. The calculator compares two equal-panel layouts and recommends the one with the shorter total unrounded fabric length.
Your measurements stay in this browser. No account or upload is needed.
Calculator
Compare your backing layouts
Use one unit throughout. Values are not converted when you change the unit label.
Measurements
Result
Enter measurements to compare plans
Required backing:
- Lengthwise
- Crosswise
Total fabric length is unrounded. This arithmetic comparison does not include directional prints, pattern matching, shrinkage or prewashing, squaring loss, damaged fabric, seam-placement preferences, pieced backs, or retailer cut increments.
How to use the quilt backing calculator
From quilt top to two comparable plans
- 01
Measure the quilt top’s width and length.
- 02
Enter the extra backing you have chosen for every side.
- 03
Enter the fabric width still usable after selvages and seams, then compare the two plans.
Worked examples
How the comparison changes
60 × 80 in quilt top
With 4 in extra per side and 42 in usable width, backing must cover 68 × 88 in. Lengthwise uses two 88 in panels (176 in total); crosswise uses three 68 in panels (204 in total).
150 × 200 cm quilt top
With 10 cm extra per side and 110 cm usable width, backing must cover 170 × 220 cm. Lengthwise totals 440 cm; crosswise totals 340 cm, so crosswise is shorter.
Before cutting
Check the assumptions against your project
Each plan uses equal-length rectangular panels. A shorter arithmetic plan may not be your preferred layout when print direction, motif matching, seam position, or the fabric itself matters.
Confirm the quilt top after pressing and squaring, verify the actual usable width, review the fabric direction and repeat, and check any quilter-specific backing requirement.
Related quilt planning
Finish the edge with a separate strip plan
After planning the back, use the quilt binding calculator to calculate straight-grain WOF strips with diagonal joins. It is a separate calculation and does not change this backing result.