Craft Calculators

SewingNo. 701

Updated October 2026

Circle Skirt Calculator

Get the waist radius, hem radius and how much fabric to buy for a full, 3/4, half or quarter circle skirt, with every way to cut it on your fabric.

Your skirt
in

Measure where the skirt will sit.

in

Waist to hem, finished.

Fabric and allowances
in
in
in

Circle skirts usually get a narrow hem, 1/2 to 1 in, because the curved edge doesn't fold up neatly.

How to calculate a circle skirt

The waist of a circle skirt is the inner edge of a ring of fabric. A full circle skirt's waist is a whole circle, so its radius is the waist measurement divided by 2π. A half circle uses half the circle, so the radius is twice as big, and so on. The hem is the same distance further out as the skirt is long.

Waist radius = waist ÷ (2 × 3.1416 × fraction of a circle) full 1, three-quarter 0.75, half 0.5, quarter 0.25 Cut waist = waist radius − seam allowance Hem radius = waist radius + skirt length + hem allowance

Example. For a 28 in waist, a full circle skirt has a waist radius of 28 ÷ 6.283 = 4.46 in. With a 5/8 in seam allowance, cut the waist at 3 7/8 in from the center. A 22 in skirt with a 1 in hem reaches 27 1/2 in from the center, so the whole circle is 55 in across. It fits on 58 in fabric in one piece, about 1 5/8 yd.

Waist radius chart

The radius of the stitching line, before taking off the seam allowance.

WaistFull circle3/4 circleHalf circleQuarter circle
24 in · 61 cm3.82 in5.09 in7.64 in15.28 in
26 in · 66 cm4.14 in5.52 in8.28 in16.55 in
28 in · 71 cm4.46 in5.94 in8.91 in17.83 in
30 in · 76 cm4.77 in6.37 in9.55 in19.10 in
32 in · 81 cm5.09 in6.79 in10.19 in20.37 in
36 in · 91 cm5.73 in7.64 in11.46 in22.92 in

Cutting and sewing tips

  • Let it hang before hemming. Parts of the hem fall on the bias and stretch. Hang the skirt for a day, then level the hem.
  • Stabilize the waist. The waist curve is partly on the bias too. Stay-stitch it right after cutting, or add a waistband or stay tape.
  • Mind the print. In one piece, a one-way print runs upside down at the back. Cut in two or four pieces to keep it upright.
  • Narrow hem, lots of it. The hem of a full circle skirt is long: a 22 in skirt has more than 4 yd of hem. A rolled hem or bias tape is easiest.

Questions

How do I calculate the waist radius for a circle skirt?

Divide your waist measurement by 2π, about 6.283, for a full circle skirt. For a half circle divide by π, about 3.142, and for a quarter circle divide by 1.571. Then take off the seam allowance to get the radius you cut.

How much fabric do I need for a full circle skirt?

The skirt is a circle twice the hem radius across, the waist radius plus the length plus the hem. A 22 in skirt for a 28 in waist is about 55 in across, so it fits in one piece on 58 or 60 in fabric, about 1 5/8 yd. On narrower fabric it is cut in two or four pieces and takes more.

What is the difference between a full and a half circle skirt?

A full circle skirt is a whole ring of fabric and has the most swing. A half circle skirt uses half a ring, so it is less full, hangs closer to the body and takes less fabric.

Do I need to add ease to the waist?

Usually not for a skirt with a waistband or zipper. The waist edge is partly on the bias and stretches a little as you sew, so stay-stitch it right after cutting. For a pull-on skirt with elastic, use your hip measurement instead so it slides over.

How long is the hem of a circle skirt?

The hem of a full circle skirt is 2π times the distance from the center to the hem line. For a 28 in waist and a 22 in skirt that is more than 4 1/2 yd of hem, which is why narrow hems or bias tape work best.

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