How the binding calculation works
- Calculate the quilt perimeter: 2 × (width + length).
- Add your editable finishing allowance for corners and closing the binding loop.
- Find the smallest whole number of WOF strips whose joined length covers that requirement.
- Multiply the strip count by the cut-strip width, then round the purchase amount up.
Why diagonal joins change the strip count
When straight-grain binding strips are joined with diagonal seams, each join consumes approximately one cut-strip width from the combined run. With n strips, this calculator models available joined length as n × usable WOF − (n − 1) × strip width. This matters near a strip-count boundary.
Use usable WOF, not just the bolt label
The width printed for quilting cotton can include selvages you will trim away. Enter the width you can actually cut. The calculator does not silently subtract an arbitrary selvage amount from your measurement.
Quilt binding FAQ
How much extra binding should I add?
The calculator starts with 12 inches by default for working room at corners and the final closing join. You can edit this allowance to match your method or pattern.
Does the calculator include fabric lost in diagonal strip joins?
Yes. For straight-grain strips joined diagonally, the model subtracts one cut-strip width for each join between strips.
What does usable fabric width mean?
It is the width you can actually cut after removing selvages. Measuring the usable width of your fabric is more accurate than entering the nominal bolt width.
Does this calculate bias binding?
No. This calculator is intentionally for straight-grain width-of-fabric strips. Bias binding needs a different cutting layout and should not be estimated with this strip model.
Is strip width the finished binding width?
No. Enter the width of the strip you will cut before folding and attaching it. Common double-fold cut widths include 2.25 and 2.5 inches.