Do I need 20 yards of tulle to make this?

You can get a distance finder or 75 foot tape measure, that will tell u the that it is 25 yards exactly.

Measure the length you want the skirt to be—wear the shoes you'll wear with the dress while you do this. Add 5/8" allowance at the waist seam and at least...

Gather the tulle by using a loose stitch, either by machine or hand stitching. Pin the new skirt to the waist seam of the original skirt to secure it in...

I would recommend netting, or whichever is stiffer. You'll need the support. Also, I would recommend wearing a long slip underneath, as both tulle and netting can feel quite scratchy...

Measure length, width, and height in yards. Estimate if you have to. Multiply the three together to get the volume.

Steps 3 & step 4 of the article show how to cut the material and stretch it over the wire to make a petal.

That depends on how fluffy you want it. Most tulle is between 2 and 6 inches; I would suggest 4 inch tulle or wider.

A good estimate is between 1.5 to 2 yards, depending on how stretchy it is. If you're a beginner, or trying this out for the first time, aim high (around...