To calculate how much binding a square of fabric will produce:
- length = area of square divided by width of binding strip
For a 20" square, area = 20" x 20" = 400" square inches
binding strip width = 2"
400" square inches area divided by 2" width = 200" binding
To estimate how large the square must be to produce the binding length you need:
- Multiply the length of the strip needed by its width to find its area.
- Determine the square root of the area to estimate the square size needed.
Strip needed is 2" wide by 250" long
2" x 250" = 500" square area
square root of 500 = 22.36
Round up and cut a 23" fabric square
The continuous binding method works best with larger pieces of fabric, because using small squares produces binding with many bulky seam allowances along its length.