Project #140 – Half Circle Skirt

This one is in a bit late because it took me a while to finish and put together the support materials.

My pattern for a half circle skirt is essentially two quarter circles stitched together. There is also another, smaller cutout of a quarter circle, indicated by the white wedge in the diagram above, that is removed the pattern piece to create the top waistline edge of the skirt. Your waist size will determine the size of the quarter circle you’ll cut. The calculations for determining this are based on solving for the radius of a circle based on its circumference.

In this case, the circumference will be twice your waist size, plus a little extra for ease and seam allowances. Why twice the size? Well, you’re making a half circle skirt, so really the waistline is only going to be 1/2 of the total circumference. We really want the radius of this big circle because it will tell us two things: how big to cut the pattern piece itself and how much to remove from the waistline.

So we know that the formula for finding the circumference for a circle:
circumference = 2π * radius
…And from that we know how to solve for the radius:

radius = circumference/2π

I got the size of my circumference by taking my waist size, adding one inch for seam allowances, and one more for ease (too tight = not comfy), and doubling that to get from a half circle to a full circle. I then solved for the radius and got a measurement of about 9.5 inches.

The radius of the big quarter circle is based on two things: how long you want the skirt to be, and your waist measurement. I wanted my skirt to be 20 inches long, so I cut a quarter circle with a 29.5 inch radius. I used a piece of paper to gauge the 90 degree angle at the origin.

Next, I cut a quarter circle with a 9.5 inch radius out of the top.

I used double fold bias tape to finish off my skirt. If you’re interested in hemming the top and bottom, just change the dimensions a little before cutting. Add an inch to the radius (for the bottom hem) and one inch less of the top wedge (for the top hem).

One Comment to “Project #140 – Half Circle Skirt”

  1. Solveig Havstad says:

    I really love this blog :) My next project will be to sew myself a skirt. Thanks!

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