Calculadora de Saia Circular
- Created by
- Renato Passos, Eng. de Software
- Reviewed by
- Renato Passos, Eng. de Software
Last updated: Apr 18, 2026
Formula
r_interno = cintura / (2π); tecido ≈ (r_interno + comprimento) × 2
About this calculator
The Circle Skirt Calculator is a practical tool for sewing enthusiasts, whether professionals or hobbyists. It calculates the inner radius needed for the waistband based on waist measurement and estimates the fabric required for the desired length. The full circle skirt is a classic style with no side seams, requiring precise cutting for a perfect fit.
The calculation works as follows: the inner radius is obtained by dividing the waist circumference by 2π (approximately 6.28). The fabric needed is estimated as twice the sum of the inner radius and the desired skirt length, considering the piece is cut from a full circle. This value is an approximation, as actual fabric depends on fabric width and pattern layout.
Use this calculator when planning a circle skirt for parties, dance, or everyday wear. It's especially helpful for beginners, helping avoid cutting errors that waste fabric. Note that the formula assumes the skirt is cut as a single piece without seams. For skirts with less fullness (half or quarter circle), the calculation differs.
Important tips: measure the waist accurately, as a 1 cm error can affect the fit. Consider fabric width: narrow fabrics may require seams. The fabric estimate does not include seam allowances, so add 2 to 5 cm extra. For patterned fabrics, buy a bit more to match the print.
Frequently asked questions
How to measure the waist correctly for a circle skirt?
Use a measuring tape around the narrowest part of your waist, not too tight. Record the measurement in centimeters. For better accuracy, measure over the undergarments you plan to wear with the skirt.
Can I use this calculator for a half-circle or quarter-circle skirt?
No, this calculator is specific for a full circle skirt (360 degrees). For a half-circle skirt (180 degrees), double the inner radius; for a quarter-circle (90 degrees), quadruple it.
What does the estimated fabric value mean?
It is the minimum fabric needed in centimeters assuming an ideal cut. In practice, buy a little extra for seam allowances and adjustments. For patterned fabric, add 10 to 20 cm for pattern matching.
Do I need to add seam allowance to the calculation?
Yes, the formula does not include seam allowances. Add 2 to 5 cm extra to the length and radius for seams and hem. Typically, include 1.5 cm for the waistband seam and 2 to 4 cm for the hem.
Does the calculator work for any fabric type?
Yes, but very stretchy or slippery fabrics may require extra care. For lightweight fabrics, the drape may differ. Always make a test with a paper pattern before cutting the fabric.