Shape & detail / FREE CALCULATOR
Circle skirt calculator
Calculate quarter, half, three-quarter or full-circle skirt radii from your finished waist and length. Check a conservative quarter-panel layout against your usable fabric width.
Make your calculation
HOW IT WORKS
Choose circle fullness, waist circumference and finished length.
Enter waist, panel-edge and total hem allowances.
Read the drafting radii and check whether the panel blocks fit your cloth.
THE WORKING BEHIND THE NUMBER
A little more clarity.
THE METHOD
Waist seam-line radius = (waist + ease) รท (2ฯ ร circle fraction). Inner cutting radius = seam-line radius โ waist allowance. Outer cutting radius = seam-line radius + length + hem.
Keep the seam line and cut line separate
The finished waist is measured along its seam line. Adding waist ease changes that circumference before the radius is calculated. The inner cutting radius is smaller because the waist seam allowance extends towards the centre of the circle. The outer cutting radius includes the skirt length and the total hem allowance.
A quarter, half or full circle uses a different portion of a circumference. The calculator accounts for that fraction rather than applying a full-circle radius to every style. The diagram is an explanation of the geometry, not a printable pattern.
Understand this fabric layout
The yardage estimate divides the style into 90-degree panels and places their conservative bounding squares in rows. It does not attempt to nest circular pieces or plan a whole circle on a fold. Extra seam allowance is reserved around each panel block.
Plan a waistband, lining, pockets and closure separately. A circular hem can change after the fabric hangs, so any allowance you want for levelling the hem belongs in your real cutting plan. Pattern matching and shrinkage are outside this geometric estimate.
A FEW USEFUL ANSWERS
Before you cut.
Why does a half circle have a larger waist radius?
The same waist circumference runs around only half a circle. Its radius must therefore be larger than the radius for a full circle at the same finished waist.
Does the fabric result include a waistband?
No. It is for the skirt panel blocks only. Add the waistband, lining, closures and other pieces in your cutting plan.
Can I use the diagram as a pattern?
No. It is not to scale. Use the numeric radii and your pattern-drafting method, then check the seam allowances and closure before cutting.
The reference shelf
Further reading on the construction or method. Calculator-specific assumptions are explained above.