Pleating Calculator

A knife pleat folds fabric in a single direction, so the fold consumes fabric equal to twice the pleat's depth -- the fabric folds under once and lies flat. A box pleat instead folds fabric from a center point in two opposing directions, effectively doubling the fold structure and consuming four times the pleat depth in fabric, which is why this calculator applies a 2x factor to knife pleats and a 4x factor to box and inverted box pleats.

No -- Pleat Spacing is calculated purely from Finished Width divided by Number of Pleats, so it's unaffected by Pleat Depth or Pleat Type; those two only change how much fabric is hidden inside each pleat, not how far apart the pleats fall across the finished panel's visible width. If you want pleats spaced differently, adjust Number of Pleats or Finished Width, not Pleat Depth.

Use the Fabric-to-Finished Ratio output as your shopping guide -- it expresses Total Fabric Needed as a multiple of Finished Width, so a ratio of 2.5x means you need roughly 2.5 times the finished width in raw fabric. Always buy a small additional margin beyond the calculated total to account for seam allowances, pattern matching, and a pressing or fitting error, since this calculator's total reflects only the fabric consumed by the pleats themselves.

An inverted box pleat is structurally the same fold as a standard box pleat -- fabric folded from a center point in two opposing directions -- the only difference is which way the folds face on the finished garment (an inverted box pleat shows its seam allowances at the fold rather than a flat panel). Because the fold geometry and fabric consumption are identical, this calculator applies the same 4x depth factor to both pleat types.