THE NUMBERS, EXPLAINED
How to use this calculator.
Ideal rectangular lay-flat geometric estimate, no stretch or gussets; verify physical fit. Orientation is fixed and corner/seam behavior is excluded.
Start with your inputs
Enter rectangular item length (mm), item width (mm), item thickness (mm), seal allowance at each end (mm), available flat bag width (mm), available bag length (mm). Keep amounts in the units shown on each field. The example is a starting point, not a recommended value.
| Input | Example value |
|---|---|
| Rectangular item length (mm) | 200 |
| Item width (mm) | 100 |
| Item thickness (mm) | 30 |
| Seal allowance at each end (mm) | 20 |
| Available flat bag width (mm) | 150 |
| Available bag length (mm) | 300 |
A worked example
With the example inputs above, required lay-flat width (mm) is 130. Change the inputs to explore your own scenario.
| Result | Example answer |
|---|---|
| Required lay-flat width (mm) | 130 |
| Required bag length (mm) | 270 |
| Fit in stated orientation | Fits geometric allowance |
| Unused flat bag area (mm²) | 9,900 |
How this is calculated
Required lay-flat width (mm)
Use half the item cross-sectional perimeter.
Required bag length (mm)
Allow thickness plus two end seals along bag length.
Fit in stated orientation
Compare both bag dimensions with required dimensions.
Unused flat bag area (mm²)
Compare supplied flat area with minimum bounding flat area.
Symbols and units
- a
- Rectangular item length (mm)
- b
- Item width (mm)
- c
- Item thickness (mm)
- d
- Seal allowance at each end (mm)
- e
- Available flat bag width (mm)
- f
- Available bag length (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
Ideal rectangular lay-flat geometric estimate, no stretch or gussets; verify physical fit. Orientation is fixed and corner/seam behavior is excluded.
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?
Required lay-flat width (mm); Required bag length (mm); Fit in stated orientation; Unused flat bag area (mm²). 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: Ideal rectangular lay-flat geometric estimate, no stretch or gussets; verify physical fit. Orientation is fixed and corner/seam behavior is excluded.
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: Describe and Identify Cost Drivers ↗
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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