THE NUMBERS, EXPLAINED
How to use this calculator.
Symmetric two-panel zipper gusset. The available tape attachment width on each side must accommodate your seam allowance; this is a cutting worksheet only.
Start with your inputs
Enter zipper tape total width (mm), desired visible zipper opening width (mm), panel seam allowance (mm), finished opening length (mm), end allowance at each end (mm). Keep amounts in the units shown on each field. The example is a starting point, not a recommended value.
| Input | Example value |
|---|---|
| Zipper tape total width (mm) | 30 |
| Desired visible zipper opening width (mm) | 10 |
| Panel seam allowance (mm) | 5 |
| Finished opening length (mm) | 200 |
| End allowance at each end (mm) | 10 |
A worked example
With the example inputs above, tape attachment width each side (mm) is 10. Change the inputs to explore your own scenario.
| Result | Example answer |
|---|---|
| Tape attachment width each side (mm) | 10 |
| Each gusset panel cut width (mm) | 15 |
| Each gusset panel cut length (mm) | 220 |
How this is calculated
Tape attachment width each side (mm)
Subtract visible opening width and divide remaining tape equally.
Each gusset panel cut width (mm)
Add panel seam allowance to tape attachment width.
Each gusset panel cut length (mm)
Add allowance at both opening ends.
Symbols and units
- a
- Zipper tape total width (mm)
- b
- Desired visible zipper opening width (mm)
- c
- Panel seam allowance (mm)
- d
- Finished opening length (mm)
- e
- End allowance at each end (mm)
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
Symmetric two-panel zipper gusset. The available tape attachment width on each side must accommodate your seam allowance; this is a cutting worksheet only.
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?
Tape attachment width each side (mm); Each gusset panel cut width (mm); Each gusset panel cut length (mm). 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: Symmetric two-panel zipper gusset. The available tape attachment width on each side must accommodate your seam allowance; this is a cutting worksheet only.
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 Prealgebra 2e — arithmetic and proportions ↗
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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