Now that I know the pleat size, it’s time to figure out what dimensions to cut the fabric to.
The length is easy, just add 13” to the desired finished length for the hems.
The width isn’t as straightforward and will be different for everyone.
Add 4” to the width to account for the amount needed to finish the sides.
If you want the fabric to attach to the wall on the sides, measure the “return” which is the distance from where the fabric hangs on the curtain rod to the wall. Having returns looks professional and eliminates the gap between the wall and the curtain. Make sure to add this distance to each panel if you want a return. For my curtain, it’s 3 ½ inches.
Also add the leading edge, which is the distance from the inner edge (opposite from the return) to the first pleat. This is generally about 4″ or so. Mine’s going to be 3 ½”.
So all together the extras you need to take into consideration are:
Return + Leading Edge + 4″ for sewing the sides
My curtain: 3.5 + 3.5 + 4 = 11″
As a starting place for the amount of fabric needed for the pleats, you can multiply the distance you want the curtain panel to cover by about 2 or 3, depending on how full you want the curtains. Or start with the maximum width of fabric you want to use, which is what I did.
To minimize the number of yards needed, I don’t want the width before sewing to be more than a width of the fabric plus a half width. For standard 54” wide drapery fabric that’s 54 + 27 = 81”. Then subtract the extra inches figured out before, which is 11″ for me. So I have 70″ to work with for my pleats.
Figure out the amount of fabric one pleat takes up. That’s the amount you see from the front plus double the size of pleat on the back.
My pleats: 3.75 + (1.5 x 2) = 6.75
Take your rough number for the total width needed for the pleats and divide by the total pleat size. For me: 70 / 6.75 = 10.4 and round down to 10. This means I can fit 10 pleats with some extra left over.
(Total pleat size x Number of pleats) + Return + Leading Edge + Amount needed to sew sides = Total width
Mock this up on a strip of the fabric to see if it all works out. If you’re using a solid fabric or don’t care where the pleats fall exactly, this is all a little more forgiving because you can make adjustments after the panel is sewn, before pleating it. But in my case, it’s important to be precise before sewing.
If you need to seam pieces together, matching the fabric up usually only takes about ½”. But you also have to take into consideration the seam location because you want the seam to be on the back of a pleat. This means you may have to shift the pleats.
If you have a pattern that you want to repeat evenly on the pleats, you may have to start the pleats in a certain spot and some of the fabric on the edges may not be usable.
Even though you have a certain amount of fullness created by the pleats, you can still make the finished width of the pleated panel larger than the distance you need to cover. This will give it extra fullness and means you don’t have to pull the curtain taught to close it all the way.
Those are the steps I took when figuring out the width and pleats, but it will be different for everyone. I hope that’s somewhat helpful!