What fullness ratio should I use?

Light gathers: 1.5×. Medium gathers: 2×. Full gathers: 2.5–3×. The ratio depends on fabric weight — lightweight fabrics (chiffon, voile) look best with higher ratios (2.5–3×); heavier fabrics need less (1.5–2×).

How do I gather evenly?

Sew two rows of long basting stitches (4mm+) within the seam allowance. Pull the bobbin threads from both ends to draw up the fabric evenly. Pin at regular intervals to distribute gathers before sewing the final seam.

Is gathering different from shirring?

Gathering creates one row of fullness at a seam line. Shirring uses multiple rows of elastic thread to create stretchy, gathered fabric over a wider area. Shirring typically uses 2–3× fullness.

SewCalcs

Gather Calculator — Fabric for Gathered Sections

Calculate fabric width needed for gathered sections based on desired fullness ratio.

Finished Width

Width after gathering

Fullness Ratio

How We Calculate This

Gathered fabric width = finished width × fullness ratio.

The formula

Fabric width = Finished width × Fullness ratio

Frequently Asked Questions

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Last updated: February 2026

All calculations are estimates. Always verify quantities before cutting or purchasing fabric.