Knife and Box Pleat Fabric Intake Calculator
Calculate flat fabric width and equal repeat positions for an entered finished pleated width.
YOUR CALCULATION
Result
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Calculation steps
Work through one step at a time or reveal the complete calculation. The steps use your current inputs.
How to calculate
Compute fabric taken into each repeat from the defined underfold depth. Add all intake and total end allowances to finished width.
Cut width=finished width+repeats×(2 depth for knife, 4 depth for box)+end allowances
Worked example
Ten knife pleats at 2 cm underfold depth over 100 cm finished width consume 40 cm, giving 144 cm flat fabric including 4 cm total end allowance.
Assumptions and input details
Depth means one underfold, not the visible pleat width or total folded intake. A box repeat is defined here as two opposing knife pleats. The result gives equal flat/finished repeat boundaries, not a universal fold-marking recipe. Up to 1000 repeats; the first 200 repeat rows are shown and omissions counted. Thickness, pressing behavior, alternating design details, hems beyond entered ends and fit are excluded.
Unit definitions
Unit selection is independent of language. Each selector contains only units for its physical quantity. Calculations use defined base units internally.
Choose from 23 length definitions, including explicitly labelled regional measures. Area conversions square the length factor; geometric volumes cube it.
Regional measures are not interchangeable merely because their names look similar. This is a documented selection, not a claim to include every historical unit.
NIST measurement tables · Japanese traditional units · Mainland China and Hong Kong unit distinctions
Using this calculator
Can I enter my own problem?
Yes. Replace the example values with your own inputs. The result, calculation steps, tables and applicable diagrams update from those inputs. Blank or invalid values clear the result; example values are never silently substituted for missing inputs.
Are the results exact?
Results use floating-point arithmetic and displayed rounding. Read the formula, assumptions and any stated data precision before interpreting the result.
Is my input uploaded?
The calculation runs in your browser. No account, file upload or external AI service is required. Inputs are not saved between page reloads.
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