How to calculate the number of strips to bind a quilt.
It is frustrating to sew your binding strips together only to find that you are short and need another strip. Here is the formula that I use. Measure the width and length of your quilt. Since fabrics come in slightly different widths, measure the width of your fabric with the selvage removed i.e. 40". I subtract 2" from the fabric width to account for the mitered corners.
Use the following formula.
((quilt width + quilt length) * 2 )/ (fabric width - 2) round to the nearest highest number.
Example
(50 + 60) = 110 * 2 = 220 / (40 - 2) = 5.79 round to 6
You will need 6 strips to bind this quilt.