Use this formula to calculate the amount of fabric you need if the fabric is wide enough to create each panel.
______ Finished Length
______ Plus the header (facing) to the bottom of the rod
__+ 1"_ Plus 1" in order to turn under 1/2" at each end of the panel
______ Plus Hem (allow 2" to 3" depending on the weight of the fabric you are using. A light weight fabric is usually better with a 3" hem to "weight" the hem and help it hang properly.
______ Equal total length needed for each panel
______ Times the number of panels
______ Divided by 36" (for a yard of fabric or 39.37" for a meter of fabric}
______ Add on for tie backs, ruffles, fabric shrinkage, extra width and other trimming desires or matching pattern repeats in print fabric.