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Circle Skirt Calculator
Draft a circle skirt without a pattern. Enter your waist measurement, the skirt length and the type of skirt — full, three-quarter, half or quarter circle — to get the waist radius to draw from the corner of your fabric and the outer radius to cut along.
- Outer cutting radius
- 26.96 in
- Finished hem circumference
- 166.23 in
Saved setups
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Your recent calculations
Results you calculate here are kept on this device so you can come back to them.
Formula
How to use it
- Measure your waist where the skirt will sit and enter it.
- Enter the finished length from waist to hem.
- Choose the skirt type and your hem allowance.
- From the corner or fold of the fabric, mark an arc at the waist radius and another at the outer radius, then cut along both.
Worked examples
A full circle skirt for a 28 in waist, 22 in long with a ½ in hem (waist radius 4.46 in, cutting radius 26.96 in — shown here in meters)
- Waist radius
- 4.46 in
- Outer cutting radius
- 26.96 in
- Finished hem circumference
- 166.23 in
A half circle skirt for a 76 cm waist, 60 cm long with a 1 cm hem (waist radius 24.19 cm, cutting radius 85.19 cm — shown here in meters)
- Waist radius
- 9.52 in
- Outer cutting radius
- 33.54 in
- Finished hem circumference
- 104.13 in
Choosing a skirt type
A full circle has the most swing and the most fabric; laid flat it is a complete ring. A half circle is a semicircle with a gentler flare and one seam, and uses about half the fabric. A quarter circle is close to an A-line. A three-quarter circle sits in between.
The fewer degrees in the skirt, the larger the waist radius: a 28-inch waist needs a radius of 4.46 inches for a full circle but 8.91 inches for a half circle and 17.83 inches for a quarter circle.
How much fabric you need
The outer cutting radius tells you. A full circle cut in one piece needs a square of fabric twice the outer radius on each side; if your fabric is narrower, cut two half circles and join them at the side seams. A half circle needs a piece twice the outer radius long and one outer radius wide; a quarter circle fits in a square one outer radius on each side.
Fabric widths are commonly 44–45 or 58–60 inches, so a knee-length full circle for an adult usually has to be cut in two pieces.
Fitting tips
The waist opening stretches because much of it is cut on the bias. For woven fabric with a zipper, many sewists subtract about an inch from the waist before calculating, or stay-stitch the edge immediately after cutting. Add seam allowance to the waist measurement if the skirt has seams, and ease if it has an elastic waist that must pull over the hips.
Hang the skirt for at least 24 hours before hemming. The bias sections drop, and the hem needs to be leveled afterwards.
Questions people ask
How do I calculate the radius for a circle skirt?
Divide the waist measurement by 6.28 (2 × π) for a full circle. A 30-inch waist gives a waist radius of 4.77 inches.
What is the waist radius for a half circle skirt?
The waist divided by 3.14 (π). A 30-inch waist gives 9.55 inches — twice the full-circle radius.
How much fabric do I need for a full circle skirt?
A square with sides twice the outer cutting radius. For a 28-inch waist and a 22-inch length with a ½-inch hem, the outer radius is about 27 inches, so you need about 54 by 54 inches, or two half circles from narrower fabric.