Stitch Math Tools
Quilt Backing Calculator
Extra fabric beyond the quilt top on all four sides.
Auto picks the lower-bulk seam layout.
Adds a little extra for squaring and cutting.
Use the allowance requested by your longarm quilter.
Common Quilt Size Presets
| Size | Quilt top | Overhang |
|---|---|---|
| Baby | 36" x 45" | 4-5 in |
| Throw | 60" x 72" | 4-6 in |
| Twin | 66" x 90" | 5-6 in |
| Full | 80" x 90" | 5-6 in |
| Queen | 90" x 108" | 5-6 in |
| King | 108" x 108" | 5-6 in |
Worked Example
- 1Quilt top size: 72" x 90"
- 2Add 5" on each side: 82" x 100"
- 3Use 44" fabric and cut 3 strips.
- 4Buy 8.8 yd after the 5% buffer.
Results
Yardage needed
8.8 yd
Panels/strips
3
Cut each strip
100 in
Seam direction
Vertical
Waste estimate
0.4 yd
Cutting Plan (Top View)
Horizontal Seams
More bulk across the middle
Not selected
Vertical Seams
Fewer seams across the quilt
Recommended
Legend
Quilt top
Backing
Seam line
FAQ
How much overhang is recommended?
Use 4 to 6 inches on each side for most quilts. Ask for the exact number if a longarm quilter will load the backing.
Why are vertical seams often better?
Vertical seams usually run with the quilt length, so the backing lies flatter and has less bulk across the middle.
Can I use 90" or 108" wide backing?
Yes. Wide backing often removes seams, but check the shrinkage and square the fabric before quilting.
What does longarm allowance include?
Longarm allowance is the extra backing needed for clamps, rollers, and take-up during quilting.
Related Tools
Cross Stitch Fabric Calculator (Preview)
Over
Design size
10.00" x 12.86"
Fabric cut size
16.00" x 18.86"