Free calculator · circular flounces
Enter the edge you are sewing to and the flounce width. Get the inner radius, the cut circles, the number of rings and a 1:1 pattern to print.
Tiled PDF: print at 100%, check the 1 in / 2 cm squares and tape the pages.
How it works
Measure the edge the flounce will be sewn to: a hem, a neckline or a sleeve.
Enter the finished width. The calculator picks how many rings fit your fabric.
Print the tiled pattern at 100%, tape the pages and cut along the circles.
Worked example
Worked example
Result
The hem edge is 1.6× the sewn edge, which is what makes it ripple. In metric, a 150.0 cm edge takes 0.8 m (7/8 yd).
The math
Each ring's inner circle is sewn to its share of the edge. Cut the inner circle smaller by the seam allowance and the outer one larger by width plus hem.
Edge per ring: 60" ÷ 1 = 60". Stitch radius: 60" ÷ 2π = 9 3⁄4". Cut inner: 9 3⁄4" − 1⁄2" = 9 1⁄4". Cut outer: 9 3⁄4" + 6" + 1⁄4" = 16".
Tips
Staystitch the inner curve before you clip it. Bias edges stretch fast.
Clip the seam allowance every few centimeters so the curve opens straight onto the edge.
A rolled or baby hem keeps the outer curve light. A wide hem fights the ripple.
For a straight, gathered ruffle instead, use the gathering ratio calculator.
A flounce is cut as a circle and ripples without gathers. A ruffle is a straight strip that is gathered.
A long edge needs a big circle. When it no longer fits your fabric, the calculator splits it into rings joined end to end.
Any width, but wide flounces need very big circles. Above about a third of the edge, expect several rings.
Yes. The cut lines include the seam on the inner edge and the hem on the outer edge. The stitch line is marked too.
Yes. Print at 100% or Actual size and measure the test square before you tape the pages.
Free, private and printable. Your numbers never leave this page.
