Circle Skirt Calculator
Calculate radii, cutting dimensions, and yardage for full, 3/4, half, and quarter circle skirts.
Results are estimates. Always add extra for shrinkage, mistakes, and pattern matching.
How to Use the Circle Skirt Calculator
Enter your waist measurement (the finished waist size, not the fabric cut) and desired skirt length. The calculator shows results for all four circle variants simultaneously so you can compare.
Circle Type Guide
- Full Circle (360°): Maximum fullness and flare. Uses the most fabric. Dramatic, twirly look.
- 3/4 Circle (270°): Very full with slightly less fabric. Great middle ground.
- Half Circle (180°): Moderate flare, fabric-efficient. One cut from folded fabric.
- Quarter Circle (90°): Minimal flare, very fabric-efficient. Two panels sewn together.
The Formula
Inner Radius = Waist ÷ (2π × fraction)
Outer Radius = Inner Radius + Skirt Length
Cutting Square = 2 × Outer Radius (full circle)
fraction: full=1, 3/4=0.75, half=0.5, quarter=0.25
Tip: Add your seam and hem allowances to the inner and outer radii respectively before cutting.
About this Circle Skirt Calculator
A circle skirt's waist opening is a circle (or part of one), so the waist measurement determines the inner radius mathematically rather than by a rule of thumb — that's what the formula above is doing. Entering a smaller fraction (half or quarter circle) doesn't change the radius math, only how many identical panels you cut and sew together to make up that same circle.
Fabric width limits which circle fits without piecing
A full or 3/4 circle skirt needs its outer radius to fit within roughly half your fabric's width to cut in one layer folded into quarters — for a wide, long skirt on narrow fabric, that often isn't possible without piecing panels together, which the half and quarter circle options avoid by design. Use your finished waist measurement (not the fabric width) as the input, and see the Fabric Yardage Calculator if you'd rather estimate yardage for a skirt more generally.