THE NUMBERS, EXPLAINED
How to use this calculator.
Evenly distributes identical knife pleats between two equal unpleated margins. A knife pleat consumes twice its depth. Spacing is the repeat pitch of pleats across the finished inner width, not a gap between folded fabric edges.
Start with your inputs
Enter fabric width after edge hems (cm), target finished width (cm), knife pleats, unpleated margin at each end (cm). Keep amounts in the units shown on each field. The example is a starting point, not a recommended value.
| Input | Example value |
|---|---|
| Fabric width after edge hems (cm) | 200 |
| Target finished width (cm) | 100 |
| Knife pleats | 10 |
| Unpleated margin at each end (cm) | 5 |
A worked example
With the example inputs above, fabric taken up per pleat (cm) is 10. Change the inputs to explore your own scenario.
| Result | Example answer |
|---|---|
| Fabric taken up per pleat (cm) | 10 |
| Pleat depth (cm) | 5 |
| Finished pleat pitch (cm) | 9 |
How this is calculated
Fabric taken up per pleat (cm)
(Fabric width − finished width) ÷ pleat count.
Pleat depth (cm)
Divide take-up per pleat by two.
Finished pleat pitch (cm)
(Finished width − two end margins) ÷ pleat count.
Symbols and units
- a
- Fabric width after edge hems (cm)
- b
- Target finished width (cm)
- c
- Knife pleats
- d
- Unpleated margin at each end (cm)
Use the units shown. A list keeps the order in which you enter its values. The symbol ^ means “raised to the power of”.
Assumptions and limits
Evenly distributes identical knife pleats between two equal unpleated margins. A knife pleat consumes twice its depth. Spacing is the repeat pitch of pleats across the finished inner width, not a gap between folded fabric edges.
Calculations use the values you enter. Blank or invalid inputs show an error instead of silently substituting zero. Results are displayed to useful precision; calculations retain the underlying numeric precision.
Questions about this tool
What does the result tell me?
Fabric taken up per pleat (cm); Pleat depth (cm); Finished pleat pitch (cm). The result applies to the method and inputs described above. Check the units and assumptions before using it in a decision.
Why might another calculator differ?
Differences in units, rounding, timing or model definitions can produce different answers. Compare the input definitions and the method, rather than only the final number. For this tool: Evenly distributes identical knife pleats between two equal unpleated margins. A knife pleat consumes twice its depth. Spacing is the repeat pitch of pleats across the finished inner width, not a gap between folded fabric edges.
Are my inputs stored or sent to AI?
Calculations on this page happen in your browser. The separate AI question finder sends its submitted conversation to OpenAI; these calculator fields are not sent. Favourites and recent tool names are stored locally. A shared link contains the inputs you choose to include.
Further reading
OpenStax: geometric formulas and arithmetic ↗
Background reading; this does not imply endorsement or independent review of SumFizz.
Review status
Software example and browser checks are recorded in our quality report. No external expert review is claimed. Created with coding assistance; calculations run as ordinary browser code.
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