Circle Skirt Calculator
Choose skirt type, enter waist and length, then click calculate.
Inputs
Results
Step-by-step
Quick summary
Use this Circle Skirt Calculator to estimate the waist radius and basic fabric length needed for a full, three-quarter, half, or quarter circle skirt.
Circle Skirt Calculation Method
The calculation is based on the circumference of a circle:
C = 2πr
For a circle skirt:
Waist radius = waist circumference ÷ (2π × skirt fraction)
The skirt fractions are:
- Full circle: 1.00
- 3/4 circle: 0.75
- Half circle: 0.50
- Quarter circle: 0.25
Once the waist radius is known:
Hem radius = waist radius + skirt length
The calculator uses the outer diameter for a basic fabric-length estimate:
Basic fabric length ≈ 2 × hem radius
Example
Suppose you want a full circle skirt with a 30-inch waist and a 24-inch skirt length.
Waist radius = 30 ÷ (2 × π) ≈ 4.77 in
Hem radius = 4.77 + 24 = 28.77 in
Basic fabric length = 2 × 28.77 ≈ 57.54 in
The basic pattern therefore has a waist radius of approximately 4.77 inches and an outer diameter of about 57.54 inches.
Important Notes
- The calculator provides basic pattern geometry, not guaranteed fabric yardage.
- Seam allowance, hem allowance, waistband fabric, closures, and wearing ease are not automatically included.
- Actual fabric requirements depend on fabric width and whether the skirt must be cut in multiple panels.
- Directional prints, nap, shrinkage, and pattern matching may require extra fabric.
- Stretchy or drapey fabrics can affect the finished waist and hem, so test the pattern before cutting expensive fabric.