Calculatium

Circle Skirt Calculator

Calculate inner and outer radii for full, half or quarter-circle skirts from waist and length. Check a reference piece width, not fabric metres.

Enter your values

The starting values are editable examples. Results update when you change your inputs.

Example: 62.8319
Example: 50
Example: 0
Example: 0
Example: 150

Your result

Updates as you change your values.

Enter values to calculate.

How it is calculated

Inner radius = waist / (2π × circle fraction). Outer radius = inner radius + skirt length + hem + radial allowance. Reference width is 2R for full/half and R for quarter circle in the fixed layout.

Worked example

A full-circle skirt with a waist of about 62.8319 cm has an inner radius of 10 cm. A 50 cm length without allowances gives a 60 cm outer radius and a 120 cm reference width.

Before you calculate

Choose the circle fraction and measure the intended waist opening. Include the hem and radial allowance once. The reference-width check uses a fixed geometric orientation; it does not choose seams, fold positions or alternative pattern layouts.

Interpreting the result

This is a geometry aid rather than a finished sewing pattern. It does not convert the radius into fabric purchase metres or allow automatically for nap, print matching, shrinkage and construction. Check the full pattern and cutting plan before buying.

Use the units shown beside each field. Monetary fields labelled EUR stay in euros; changing language does not exchange currencies. Results are estimates under the stated assumptions.