THE NUMBERS, EXPLAINED
How to use this calculator.
Uses the internal box volume less the item displacement. Bulk density must describe the installed fill. Packing geometry, compression and protective performance are not inferred.
Start with your inputs
Enter internal box length (cm), internal width (cm), internal height (cm), packed item displacement (l), fill bulk density (g/l). Keep amounts in the units shown on each field. The example is a starting point, not a recommended value.
| Input | Example value |
|---|---|
| Internal box length (cm) | 40 |
| Internal width (cm) | 30 |
| Internal height (cm) | 20 |
| Packed item displacement (L) | 10 |
| Fill bulk density (g/L) | 20 |
A worked example
With the example inputs above, void volume (l) is 14. Change the inputs to explore your own scenario.
Putting the example numbers into the formula
Void volume (L)
(40) × (30) × (20) ÷ 1000-(10) = 14
Estimated fill mass (g)
((40) × (30) × (20) ÷ 1000-(10)) × (20) = 280
| Result | Example answer |
|---|---|
| Void volume (L) | 14 |
| Estimated fill mass (g) | 280 |
How this is calculated
Void volume (L)
a × b × c ÷ 1000-d
Estimated fill mass (g)
(a × b × c ÷ 1000-d) × e
Symbols and units
- a
- Internal box length (cm)
- b
- Internal width (cm)
- c
- Internal height (cm)
- d
- Packed item displacement (L)
- e
- Fill bulk density (g/L)
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
Uses the internal box volume less the item displacement. Bulk density must describe the installed fill. Packing geometry, compression and protective performance are not inferred.
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?
Void volume (L); Estimated fill mass (g). 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: Uses the internal box volume less the item displacement. Bulk density must describe the installed fill. Packing geometry, compression and protective performance are not inferred.
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: algebra and proportional reasoning ↗
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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