Formula
- Use the units shown beside each field.
- Results update automatically whenever you change an input.
- Displayed values use up to four decimal places, or scientific notation for very small or large numbers. Calculations use standard floating-point arithmetic; exact integer and fraction tools identify their own precision rules.
- Equal knife pleats. Depth means one underfold side; waistband, hem, closure and fabric shrinkage are excluded.
Example Calculation
- Finished waist: 72 cm
- Pleats: 12
- Underfold depth per side: 2 cm
- Total seam allowance: 2 cm
72 cm waist, 12 pleats with two 2 cm underfolds each and 2 cm seams require 122 cm width.
Frequently asked questions
How do I use this calculator?
Enter finished waist, pleats, underfold depth per side, total seam allowance. The result updates automatically. Use Reset to restore the example values.
What method does it use?
cut width=waist+2 × pleat count × underfold depth+seam allowance.. Equal knife pleats. Depth means one underfold side; waistband, hem, closure and fabric shrinkage are excluded.
Why might a rounded result differ?
The calculation keeps full numeric precision internally, then rounds the displayed result. Rounding intermediate steps by hand can produce a slightly different answer.
Are my inputs saved online?
No. This calculator processes your inputs in your browser. A recently used list stores only calculator names on this device, not your entered values.
Check the assumptions and units before using this result. Read about calculation methods.