Tutorial: 3/4 Circle Skirt (includes sewing instructions)

Here is the tutorial I promised in Monday's post. Like I said then, when I was making my 3/4 circle skirt, there didn't seem to be many tutorials online for how to put one together after you figure out your radius. There are some great circle skirt calculators out there, but I'm talking about what to do after you calculate. If you know of any and I'm just missing them, feel free to link them up in the comments!

On my previous post, the By Hand London circle skirt app was mentioned in the comments, and it's awesome! They have 1/4, 1/2 and full circle skirt functions. They also have a few posts for what to do after, like attach a waistband and insert a zipper. But I wanted to expand on what to do in between - how to make a pattern piece and how to go about splitting up your circle into smaller sections to become the pieces of your skirt.

First, you'll need to calculate your radius. I used Patty the Snug Bug's calculator because she has a 3/4 column, plus it's a downloadable Excel spreadsheet so you can keep it on your computer and always have it. Plug in your waist measurement (make sure you're using the 3/4 column!) and then round your radius measurement to the nearest 1/4". My waist is 27", so my radius is 5.25".

PATTERNING

First let's talk about what a 3/4 circle skirt is. Just as the name implies, when it's flat, it looks like three quarters of a circle (aka an 8 slice pizza with 2 slices missing).

WHO WANTS PIZZA NOW?? *raises hand*

So, we need to fit that shape onto our fabric. If your fabric is wide enough, your skirt short enough, and your waist petite enough, you might be able to fit it on your fabric in one big piece. However, that is a lot of "if's"; it would also, in my opinion, be a huge pain in the booty, because you'd have to draw a giant circle very accurately. It's a lot easier to be accurate when you're working with smaller pieces.

So, since we have a front and a back, we'll divide the shape in half: half for our front, half for our back.

I did a center back zipper for a few reasons - sometimes I don't like how zippers hang on side seams, and I also wanted to easily add side seam pockets. So for a center back zipper, we need to divide one of those halves in half again.

So here's an overview of how our skirt will go together. Two quarters in the back joined by a zipper, and two quarters in the front cut in one piece.

(At the risk of being confusing, I want to clarify - I'm dividing the skirt into four pieces, so I'm calling them quarters, but they aren't quarters of a full circle, they are quarters of a 3/4 circle.)
Now, we want to make our pattern pieces as quickly as possible using as little effort and pattern paper as possible. Or at least I do. Call it lazy, call it efficient. Call it, let's just get to the sewing part already. So we are going to make just one paper pattern piece to fulfill our requirements.
But first, we math!
Our friend geometry will help us figure out how long the upper curved edge of our piece will be. Here we go:
1. First we need to figure out the circumference of the circle of which our 3/4 circle is a part (the purple ring). The circumference of a circle is 2 x pi x radius. So, multiply your radius by 2 and then by 3.14.
2. Now we need to find out what 3/4 of this circumference is (the pink ring). So multiply the result of step one by .75. To keep things simple, round to the nearest 1/4".

(Note: I'm using my radius of 5.25" - make sure you use your own radius measurement!)
So now we know the total length of the top curved edge of our 3/4 circle skirt. Next we need to figure out what a quarter of it is (the green line in the next drawing) so we can break our skirt into four pieces.
3. Multiply the total length of the 3/4 circle skirt edge by .25. Round to the nearest 1/4". Remember this number. Mine is 6.25".

Now that we have our numbers ready, it's time to draw the pattern piece.
On a large piece of paper, draw a straight line with a yardstick. Mark out from the end the distance of your skirt radius. This is the number that the circle skirt calculator gave you in the beginning.

Now start marking points, rotating the ruler a little between each one, measuring out from the end of the original line - I'm going to call this the axis - and marking the skirt radius point. Make sure the end of your ruler is always on axis as you're measuring. Mark enough points to draw a curve. (The dotted lines show ruler placement.)

Keep going until your curved line measures the value of the green line we figured out earlier. Use a tape measure or other flexible tool and measure along the curve. At that point, draw another straight line from the axis out through the curved line.

Now determine what you want your finished skirt length to be, and your hem allowance, and add them together. My skirt was 20" and my hem allowance was only 1/4" because I hemmed with bias tape. So for the next step I was measuring 20.25".
Using the same procedure as above, measure your skirt hem distance away from the first curved line, marking points and connecting into a curve. Make sure your ruler is still going through the axis with each mark. I like to use a yardstick and keep the 0 end out at the hem; every time I rotate and mark, I make sure that the skirt hem measurement is even with the curved line, and the yardstick is also passing through the axis.

The last thing to do is add our seam allowances. You can use whatever you think is easiest. I did 3/8". Use a ruler to add your seam allowance amount to the straight edges and the smaller curved edge. Whatever seam allowance you choose, write it on your pattern piece so you don't forget.
Then cut out your pattern piece.

THE PROTRACTOR WORMHOLE
If you have a protractor and you know how to use it, you can skip most of the preceding steps. Draw a 67.5° angle on your paper (67.5° is 1/4 of 270°, which is 3/4 of 360°); that angle sets the outer bounds of your pattern piece. Measure the skirt radius points, then the skirt hem points, and add seam allowances.
CUT THE FABRIC
So here's how we're going to cut our fabric using only one paper piece. Depending on the width of your fabric, you may have to open it up and refold it the other direction to get your pieces to fit.
For the front, cut one piece on the fold, letting the seam allowance of one straight edge hang over the fold. You can also crease back the paper if that's easier. After cutting, notch your center.
Then, use the pattern piece to cut 2 backs, with one straight edge parallel to the fold/selvage. This edge is the center back. Mark it on both pieces.

You'll also need a waistband. Here is how you figure out cutting dimensions:
LENGTH: waist measurement 1" (2 x (seam allowance of back seam)) WIDTH: (2 x (desired finished width)) (2 x (seam allowance of shorter curved edge))
Notch the center of the waistband's long edges.
SEW THE THING
Staystitch upper curved edge of skirt pieces. (This means stitch through a single layer 1/8" smaller than your seam allowance.)
Stitch skirt backs to skirt fronts at side seams, right sides together. Finish and press open.
Interface waistband. Fold in half lengthwise, wrong sides together, and press to crease. Reopen. Pin one long edge of waistband to top edge of skirt, right sides together, matching ends and center front notch, and easing the skirt in to fit the waistband. Stitch together and press seam allowance up.

Install invisible zipper on back center seam with zipper stop just below crease in waistband. Stitch the rest of the seam, finish and press open. (Here is an invisible zip tutorial if you need help.)
Press raw edge of waistband a scant seam allowance to the wrong side. (ex. if your seam allowance was 1/2", fold it a teeny less than 1/2" and press). Fold waistband around zipper, right sides together. Use a zipper foot to stitch waistband down along zipper. Make sure bottom of waistband stays folded when you stitch over it.
Clip corner and turn waistband to inside. Pin all the way around, covering waist seam allowance, and then stitch in the ditch from the outside to secure waistband on the inside.

Let your skirt hang overnight, then hem as desired.
I hope that was helpful! If there are any parts that need clarification, please ask in the comments.