We factored in 8 per pleat an additional 3 on each side for the depth of the board to wrap around the return or the side of the board 1 2 for the 1 4 hem on each side and about a 1 2 for each end to wrap around the back of the board equaling 65 5 total in length.
Box pleat curtain tutorial.
I altered her tutorial just a bit and made my own box pleat curtain.
Return leading edge 4 for sewing the sides.
So this is how i did my math.
She does a great job describing how to measure how much fabric you will need with the addition of the pleats hems etc.
For my curtain i only wanted 1 pleat.
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.
6 30 it should say lining width face fabric width 6 inches instead of 3 inches.
Pin your pleats so they measure 8 inches and top stitch 8 inches down on both sides of each pleat making sure to back tack at the bottom.
Press all the pleats flat with an iron creating a 3 inch pleat so that the seam is behind the exact center of the pleat.
Once you have cut your fabric lay the ride side of your drapery fabric down on top of your lining.
Get the fabric supplies you need at onlinefabricstore.
If you are mounting your curtain on a 1 4 board you need to add 5 for the ends of the board and 8 for the pleat in the middle.
My window is 46 wide.
My board was 42 wide.
3 5 3 5 4 11.