Pleated Fabric Width Calculator
This works in knife pleats. One knife pleat consumes three times its depth, but one of those three is the face you can see, which is already counted in the finished width — so what you have to add is twice the depth per pleat. A 50 cm finished panel with ten 4 cm pleats is cut at 50 + 10 × 8 = 130 cm. Pack them so the visible face equals the depth and 12.5 pleats fit, making the fabric exactly 3× the finished width at 150 cm: that is where "knife pleats take three times the depth" comes from. Box pleats fold both ways and take four times the depth instead.
Your numbers
Cut width
130cm
Fabric the pleats consume
80cm
Formula
Cut width = Finished width + Pleats × 2 × Pleat depth
Pleats are stitched into the waist seam while folded, so three layers of cloth stack up in that seam. In denim or tweed you have to cut the depth or the count before the needle will go through. On a printed fabric, match the depth to the print repeat or the pleats will slice the pattern apart.
What to enter
| Input | Default | Accepted range |
|---|---|---|
| Finished width (cm)The width when finished, before any seam or fold allowance. | 50 | 1 and up |
| PleatsHow many pleats you are folding into the finished width. | 10 | 0 and up |
| Pleat depth (cm)How deep the fold goes underneath, not the width you see. | 4 | 0 and up |
Step by step
Quick reference table
Results when only Finished width (cm) changes and everything else stays put.
| Finished width (cm) | Cut width (cm) | Fabric the pleats consume (cm) |
|---|---|---|
| 25 | 105 | 80 |
| 37.5 | 117.5 | 80 |
| 50 | 130 | 80 |
| 75 | 155 | 80 |
| 100 | 180 | 80 |
What each result means
| Result | At default values |
|---|---|
| Cut width (cm)The width to cut — finished size plus allowance. | 130 |
| Fabric the pleats consume (cm)The extra width the pleats swallow — twice the depth for each one. | 80 |
Common mistakes
Pleats are stitched into the waist seam while folded, so three layers of cloth stack up in that seam. In denim or tweed you have to cut the depth or the count before the needle will go through. On a printed fabric, match the depth to the print repeat or the pleats will slice the pattern apart.
Glossary
- Finished width
- The width when finished, before any seam or fold allowance.
- Pleats
- How many pleats you are folding into the finished width.
- Pleat depth
- How deep the fold goes underneath, not the width you see.
- Cut width
- The width to cut — finished size plus allowance.
- Fabric the pleats consume
- The extra width the pleats swallow — twice the depth for each one.
Frequently asked questions
Q. How is Pleated Fabric Width Calculator calculated?
Cut width = Finished width + Pleats × 2 × Pleat depth — This works in knife pleats. One knife pleat consumes three times its depth, but one of those three is the face you can see, which is already counted in the finished width — so what you have to add is twice the depth per pleat. A 50 cm finished panel with ten 4 cm pleats is cut at 50 + 10 × 8 = 130 cm. Pack them so the visible face equals the depth and 12.5 pleats fit, making the fabric exactly 3× the finished width at 150 cm: that is where "knife pleats take three times the depth" comes from. Box pleats fold both ways and take four times the depth instead.
Q. Can you walk through an example?
With Finished width 50cm, Pleats 10, Pleat depth 4cm, the answer is Cut width 130cm.
Q. What do I need to enter?
Enter Finished width, Pleats, Pleat depth. The result recalculates as you type, and an empty box counts as zero.
Q. How much does the answer move if I change a number?
Changing only Finished width (cm) moves the answer to Finished width (cm) 25 → Cut width (cm) 105 and Finished width (cm) 100 → Cut width (cm) 180. The table below lays out five steps.
Q. How are the numbers rounded?
Money is shown to the nearest whole unit, percentages to one decimal place and everything else to two. What you see is rounded; the calculation itself carries the unrounded value forward.
Q. Anything to watch out for?
Pleats are stitched into the waist seam while folded, so three layers of cloth stack up in that seam. In denim or tweed you have to cut the depth or the count before the needle will go through. On a printed fabric, match the depth to the print repeat or the pleats will slice the pattern apart.
Related calculators
Materials differ in density and absorption. If your label states a figure, use it — the defaults here are only common values.