Sewing calculator

Pleat and Gather Calculator

Convert finished width and fullness ratio into source width and repeat counts.

Your measurements

Use one unit for every dimension in this form.

Select the shaping style.

Width after gathering or pleating.

Source width divided by finished width.

Finished repeat width; ignored for gathers.

Pleats and gathers result

Source width
80.00 in
Take-up
40.00 in
Complete repeats
Not applicable
Fullness planA scaled planning diagram. Use the matching text result and cut list for exact dimensions.gather2× fullness
Fullness plan. The drawing is scaled for comparison; written dimensions control.

Formula

Source width equals finished width times fullness ratio; pleat repeats use whole repeat widths plus a separate remainder.

Assumptions

  • The fullness ratio is selected for the actual fabric and style.

When a tested commercial pattern gives different cutting dimensions or layout instructions, follow that pattern.

Worked example

  • 40 in finished width
  • 3× fullness
  • 4 in repeat

The source width is 120 inches with ten complete pleat repeats.

Verification note

Pin or baste a short sample because fabric weight changes how a ratio looks in practice.

Learn and verify