Quilt backing fabric
Estimate equal-length backing panels with edge overhang and seams.
How this works
Joined panel width = n × fabric width − 2 × seam allowance × (n−1); choose the smallest sufficient n.
Example
Using the example inputs, backing fabric length is 4.8 m.
- Quilt width
- 180 cm
- Quilt length
- 220 cm
- Overhang on every edge
- 10 cm
- Usable fabric width
- 110 cm
- Seam allowance on each joined edge
- 1.5 cm
- Backing fabric length
- 4.8 m
Scope and assumptions
Parallel full-length panels; no directional pattern matching or quilting-machine specific allowance.
OpenStax mathematics reference