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Circle Skirt Calculator: Radius, Yardage, and Fabric Width

Calculate waist and hem radii for a quarter, half, or full circle skirt and the fabric width that footprint needs.

Your measurements

Use one unit for every dimension in this form.

Body or waistband measurement.

Extra room added at the waist.

Allowance outside the waistline.

Allowance beyond finished skirt length.

Finished vertical skirt length.

Usable width available for the entire conservative sector footprint.

Select the intended circle fraction.

Optional percentage added before cutting waste.

Optional percentage for layout and cutting waste.

Circle skirt result

Waist radius
4.93 in
Outer radius
26.43 in
Fabric to buy
1.500 yd
Circle skirt radiiA scaled planning diagram. Use the matching text result and cut list for exact dimensions.fullfull-circle conservative sector bound
Circle skirt radii. The drawing is scaled for comparison; written dimensions control.

Formula

Waist radius comes from arc length divided by the selected circle angle; allowances and skirt length form the outer radius.

Assumptions

  • The conservative sector footprint must fit the fabric width.
  • No extra panel seams are invented.

When a tested commercial pattern gives different cutting dimensions or layout instructions, follow that pattern.

Worked example

  • 80 cm waist + 2 cm ease
  • Full circle with 1 cm waist seam
  • 50 cm length + 2 cm hem on 120 cm fabric

The waistline radius is 13.051 cm and the outer radius is 66.051 cm, so the conservative footprint is 132.101 × 132.101 cm. It does not fit within 120 cm of usable width, and the calculator does not invent panel seams.

Verification note

Draw the radii on paper and confirm the waist opening against a waistband or muslin.

Learn and verify

Questions from search

How do I calculate a circle skirt radius?

Add ease to the waist, divide by the circle fraction times pi, then add the waist seam allowance. The outer radius is that waist radius plus length and hem allowance.

What fabric width does a full circle skirt need?

A full circle needs a square at least twice the outer radius, unless you piece the skirt. The calculator reports that conservative footprint against your fabric width.