Circle Skirt Calculator

Quick answer

The circle skirt calculator works out the waist radius to cut for a full, three-quarter, half or quarter circle skirt from your waist measurement, the outer radius from the skirt length and hem, and the fabric you need.

Waist radius to cut
3.83
Outer (hem) radius
26.83
Fabric width needed
53.7
Fabric length needed
53.7

A circle skirt is cut as a ring of fabric: the inner circle fits the waist and the outer edge forms the hem. Fuller skirts (full circle) drape in deep folds; half and quarter circles use less fabric and sit flatter. For wide skirts the full circle is usually cut as two half circles because fabric is rarely wide enough.

How to use the Circle Skirt Calculator

  1. Skirt type
  2. Waist
  3. Skirt length
  4. Hem allowance
  5. Waist seam allowance

Results update as you type, and every field accepts the units shown in its menu.

How it works

Choose the skirt type, enter your waist, the finished length, hem allowance and seam allowance.

Inputs explained

Field What to enter
Skirt type Choose one: Full circle, Three-quarter circle, Half circle, Quarter circle
Waist Units: in, cm
Skirt length Units: in, cm
Hem allowance Units: in, cm
Waist seam allowance Units: in, cm

What each result means

  • Waist radius to cut = [Skirt type]×[Waist]÷(2×pi) – [Waist seam allowance]
  • Outer (hem) radius = [Waist radius to cut] + [Skirt length] + [Hem allowance]

Example values

How the main result changes when Waist changes and everything else stays at the example values above:

Waist (in) Waist radius to cut (in)
14 1.6
21 2.72
28 3.83
35 4.95
42 6.06
56 8.29

Formula

Waist radius r = k × waist ÷ 2π − seam allowance (k = 1 full, 4/3 for ¾, 2 half, 4 quarter) Outer radius R = r + length + hem Fabric: full circle needs a square of 2R (or two half circles)

Worked example

Inputs: Skirt type: Full circle; Waist: 28 in; Skirt length: 22 in; Hem allowance: 1 in; Waist seam allowance: 0.625 in.
Results: Waist radius to cut = 3.83 in; Outer (hem) radius = 26.83 in; Fabric width needed = 53.7 in; Fabric length needed = 53.7 in.

Frequently asked questions

How much fabric for a full circle skirt?

A square with sides twice the outer radius. For a 22 in skirt on a 28 in waist, about 54 × 54 in, or about 3 yards of 45 in fabric cut as two halves.

Why subtract the seam allowance from the waist radius?

So that after sewing the waistband the finished waist matches your measurement.

Do I need a zipper?

Usually yes, unless the waistband is elastic.

Cite this calculator

Speedy Calculator. (2026). Circle Skirt Calculator. Speedy Calculator. https://speedycalculator.com/calculators/everyday-life/circle-skirt/