Most instructions tell you to make them 2 to 3 times the width of the window for fullness. It is a personal choice -I usually do l and a half times the width as I don't like to have the valance so full you don't see the pattern. Try it and see what you like best....gather some fabric in your hand and see if you like it tightly bunch or half bunched...that is my test. I wing it from there. Not much help - just MHO. budster

If it's a heavyweight fabric, make it 2x the width, if it's a light to mediumweight, make it 2 1/2x, if it's a sheer, make it 3 to 4x.

Thank you so much. Just to be on the safe side I had bought twice the width. It's on the heavy side so will just use it all and if it's too much I will just cut it. Now to get to sewing. ;-) Angie