Circle Skirt Calculator
Making a circle skirt? Enter your waist measurement, desired length, and skirt type to get the exact waist radius and fabric yardage you need. Supports full, half, three-quarter, and quarter circle skirts with customizable seam and hem allowances.
How circle skirt math works:
A circle skirt is cut from a donut shape of fabric. The inner circle is your waist opening and the outer edge is the hem. The key formula is:
Waist Radius = Waist / (2 x PI x Circle Fraction)
For a full circle, the fraction is 1. For a half circle, it is 0.5. This radius tells you where to draw the inner curve when cutting.
Skirt types:
- Full circle -- maximum flare, uses the most fabric. Great for formal wear and swing skirts.
- 3/4 circle -- slightly less flare than full, good balance of flow and fabric use.
- Half circle -- moderate flare, very popular for everyday skirts. Uses roughly half the fabric of a full circle.
- Quarter circle -- subtle flare, closest to an A-line. Most fabric-efficient.
Cutting tips:
- Fold your fabric in half (or quarters for a full circle) to cut symmetrically
- Use a yardstick or string compass to draw smooth curves
- Let the skirt hang for 24 hours before hemming -- bias-cut fabric stretches and the hem will become uneven
- Narrow hems (1/4 to 1/2 inch) work best on circle skirts since wider hems pucker on curves