Pleat calculator
Plan evenly repeated knife pleats from raw fabric width, finished width and the number of pleats. Download every fold mark.
1–1,000 equal knife pleats. Raw fabric after edge allowances must exceed finished width. Box pleats and fabric-thickness effects are not modeled. Change the input or settings to update your result. Results update as you type. Up to 1,000,000 characters.
Your result
How to use Pleat calculator
- Enter your measurements, rates or supplied recipe.
- Review the quantities, rounding and plan details.
- Download the result and verify it against your actual materials or a sample.
Useful next steps
Reserve the edge allowances
The finished pleated span excludes the two raw edge allowances. The remaining fabric is split into repeats. Every knife pleat consumes twice its fold depth; the visible finished pitch is the target span divided by the pleat count.
Mark placement, underfold and fold lines
With 150 cm raw fabric, 1 cm on each edge, a 50 cm finished span and ten pleats, the finished pitch is 5 cm and fold depth is 4.9 cm. Bring each fold line to its placement line, with the underfold halfway between. All distances are measured from the left raw edge.
Save the plan
Download the result as CSV, plus a text or JSON report with formulas, values and assumptions. Everything is calculated on your device. Changing units keeps the entered numbers, so check the selected units before using the plan.