Circle Skirt Calculator
Enter your waist measurement and skirt length to get the exact cutting radius and fabric size.
This tool is for informational and educational purposes only. It is not a substitute for professional financial, medical, legal, or engineering advice. See Terms of Service.
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Request a ToolHow to Use the Circle Skirt Calculator
A circle skirt is cut from a circle (or portion of a circle) of fabric. The key measurement is the inner radius — the distance from the center of the fabric circle to where the waist seam will be. This calculator gives you that radius along with the minimum fabric dimensions to buy.
- Enter your waist measurement. Measure your actual waist (or the waist of the person the skirt is for) in inches. This is the circumference, not the radius.
- Enter the skirt length. This is the finished length from waist to hem. A mini skirt might be 15–18", a knee-length skirt 22–25", and a maxi 35–40".
- Choose the circle type. A full circle gives the most flare and uses the most fabric. A half circle uses half the fabric with moderate flare. A quarter circle uses the least fabric with a more A-line silhouette.
- Read your cutting dimensions. The inner radius is the circle you cut out at the center for the waist. The outer radius is where you cut the hem. The fabric dimensions show the minimum square or rectangle to buy.
About the Circle Skirt Calculator
The inner radius formula derives from the relationship between circumference and radius: for a full circle, r = C / (2π). For a half circle, the waist uses only half the circle's circumference, so the radius needed to achieve the same waist size is r = C / π. For a quarter circle, r = 2C / π. The outer radius equals the inner radius plus the skirt length plus 0.5" for the top seam allowance. A separate hem allowance is not included — add your preferred hem depth to the skirt length before entering it. All calculations run locally in your browser.
Frequently Asked Questions
How much fabric do I need for a full circle skirt with a 28" waist?
For a 28" waist with a 24" skirt length, the inner radius is about 4.5" and the outer radius about 29". A full circle skirt requires a square of fabric at least 60"×60" (the diameter of the full circle). That is approximately 1.7 yards of 60" wide fabric. For a knee-length full circle skirt, plan on at least 2 yards of fabric 60" wide or 3 yards of 45" wide fabric.
What is the difference between a full circle and half circle skirt?
A full circle skirt is cut from a complete circle of fabric and has the maximum possible flare and volume. It flows and twirls dramatically. A half circle skirt is cut from a semicircle and has moderate flare — more than an A-line but less than a full circle. The half circle uses about half the fabric of a full circle but requires the inner radius to be twice as large to achieve the same waist circumference. A quarter circle skirt has the least flare and the largest inner radius.
Should I add seam allowance to my waist measurement before entering it?
No. Enter your actual body waist measurement. The calculator gives you the cutting radius for the waist opening. When you sew the waistband, you will add seam allowance to the waistband piece separately. The skirt itself only needs the waist opening to match your body measurement (or waistband measurement). Add ease (0.5–1") to the waist measurement if you want a more comfortable fit.
How do I cut a circle skirt from the fabric?
Fold the fabric in quarters (for a full circle). Pin the corner at the fold point. Tie a string to a fabric marking pen and cut the string to the length of the inner radius. Swing the pen around from the fold corner to draw the waist arc. Extend the string to the outer radius and draw the hem arc. Cut along both arcs. Unfold and you have a full circle skirt. For a half circle, fold the fabric once (not twice) and use the same method.