Circle Skirt Radius and Cloth Area Calculator
Calculate waist seam radius and outer cut radius for quarter, half, full or double circle skirts.
YOUR CALCULATION
Result
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Calculation steps
Work through one step at a time or reveal the complete calculation. The steps use your current inputs.
How to calculate
Match the selected fraction’s inner arc to waist plus entered ease, then add finished drop and radial hem allowance to the waist seam radius.
Waist radius=(waist+ease)/(2π×circle fraction); outer cut radius=waist radius+drop+hem
Worked example
A 72 cm waist seam arc on one full circle needs radius 72/(2π)≈11.4592 cm. With 60 cm drop and 2 cm hem, outer cut radius is about 73.4592 cm.
Assumptions and input details
Waist radius is a seam-line reference. This does not deduct an inward waist seam allowance or add panel-seam allowances, a waistband, zip opening or fasteners. Double circle means total arc angle 4π distributed over panels; it is not a single nonoverlapping annulus. Cloth area is ideal sector geometry, not a fabric-width nesting or purchase-yardage result. Drape, bias growth, grain and fitting are separate.
Unit definitions
Unit selection is independent of language. Each selector contains only units for its physical quantity. Calculations use defined base units internally.
Choose from 23 length definitions, including explicitly labelled regional measures. Area conversions square the length factor; geometric volumes cube it.
Regional measures are not interchangeable merely because their names look similar. This is a documented selection, not a claim to include every historical unit.
NIST measurement tables · Japanese traditional units · Mainland China and Hong Kong unit distinctions
Using this calculator
Can I enter my own problem?
Yes. Replace the example values with your own inputs. The result, calculation steps, tables and applicable diagrams update from those inputs. Blank or invalid values clear the result; example values are never silently substituted for missing inputs.
Are the results exact?
Results use floating-point arithmetic and displayed rounding. Read the formula, assumptions and any stated data precision before interpreting the result.
Is my input uploaded?
The calculation runs in your browser. No account, file upload or external AI service is required. Inputs are not saved between page reloads.
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