Fabric, amount will depend on what your end size needs to be. For my daughter, who is 18 months old, 1 yard was plenty with a bit extra to make something else.
Elastic, I prefer 2 inch wide for these types of skirts.
Instructions
First, you will need to do a little math. We need to figure out the radius so we can cut out the right size circle for the waist. Radius=circumference (your child's waist + 1 inch for a little give in the skirt) ÷ 2π ( a.k.a. 2 x 3.14) So for example, my daughter's waist is roughly 17 inches + 1 =18. 18 ÷ 6.26 = roughly 3. I made 1/4 donut pattern cutting out a 3 inch spot on the bottom.
Her skirt was roughly 8 inches long so from that 3-inch circle I measured another 8 inches and marked it again. Normally if you are using a cotton fabric or a fabric that needs a finished edge you should add another inch to the length.
I cut out my pattern and placed it on top of my fabric which was folded in fourths. I then cut my skirt from that pattern.
You should be left with 1/4 of a circle. 🙂 Don’t worry if the middle waist area looks big. We will be gathering it with the elastic which gives it that nice bouncy circle look!
Next you will need to cut your elastic about 1/2 an inch longer than your child’s waist. Some sewists prefer to cut the elastic even longer but for my daughter I didn’t feel it was necessary. Sew your elastic together.
Now you will want to pin your elastic to the top edge of your skirt. I pinned the front middle, back middle, and then the middle of both sides. After I secured those four spots I added pins equally around the skirt. You only need to pin enough of your fabric for your machine needle to sew it to the elastic waistband. Again, if you are using a fabric that will fray you may want to serge or zig zag stitch the top of your skirt before sewing it to the elastic.
Once all the pins are in place begin sewing your elastic to your skirt. Make sure you are pulling the elastic taut as you are sewing to prevent any gaps of fabric and to give the skirt the nice full appearance.
If you are using a fabric that will fray now is the time to sew the bottom edge of the skirt. For my daughter’s skirt I just left the edges unfinished since they wouldn’t fray.