Pencil Pleat Calculator — Tape & Fabric
Calculate fabric and tape for pencil pleat curtain headings.
How We Calculate This
Pencil pleat curtains use heading tape that draws up into even, closely packed folds. Fabric quantity depends on fullness ratio and the heading tape width determines the heading allowance.
The formula
Total width = Track width × Fullness ratio
Usable width = Fabric width − 2 × Selvedge trim
Widths per curtain = ceil((Total width ÷ Curtains) ÷ Usable width)
Fabric widths = Widths per curtain × Curtains
Heading allowance = Tape width + 3cm
Cut drop = Drop + Hem + Heading allowance
Tape = Fabric widths × Fabric width + ~10cm per curtain (≈20cm for a pair)
Selvedges are trimmed before the widths are joined, so the usable gathering width per width is the fabric width minus twice the selvedge trim. For patterned fabric each cut drop is rounded up to a whole pattern repeat and one extra repeat is added to the total so the design can be matched across joined widths.
Frequently Asked Questions
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Last updated: February 2026
All calculations are estimates. Always verify quantities before cutting or purchasing fabric.