While the standard shower curtain measures 72 inches square, sizes for shower curtains can vary. Making a shower curtain that is customized to fit your bathroom is actually very simple. In addition to the size of the shower opening, the needed fabric yardage for this project will depend upon other factors including how long you want the shower curtain to be and the amount of gather desired.
Measure shower area
Measure the width of the shower area from wall to wall. Multiply this measurement by 1.5 to find out how wide the fabric for the shower curtain should be. If the your bathroom has a curved rather than a straight shower curtain rod, measure the curved rod rather than the width of the shower opening. For a fuller gather, multiply the shower width by 2.
Now measure the area from the shower curtain rod down to where you want the shower curtain to end. Add 9 inches to this measurement and this will tell you how long the fabric for the shower curtain should be. This additional 9 inches is to allow for top and bottom hems.
For example, if the desired length of the shower curtain is 75 inches, add 9 inches to accommodate the top and bottom hems for a total of 84 inches. If the desired width of the shower, including gather, is 75 inches, add 3 inches to allow for side hems for a total width of 78 inches.
Use your measurements to determine how much fabric you will need. Fabric comes in a variety of widths ranging from 36 inches to 60 inches wide or larger. To make a shower curtain, you will need to select a fabric that is at least 40 inches wide.
Since no width of fabric is large enough to cover the entire area needed for a shower curtain, a lengthwise seam in the center of the shower curtain will be necessary. For example, to create a finished shower curtain that measures 75 inches by 75 inches, you will need two fabric panels that measure 84 inches in length and 40 inches in width, allowing a 1/2-inch for the center seam.
Once you have selected a fabric that is at least 40 inches wide, divide your length measurement by 36 to calculate yardage. An 84-inch length will require 2 and 1/3 yards of fabric.
If the fabric that you have selected has a large print, make sure to allow for more fabric so that you can match the print at the seam. An additional yard should suffice.