THE NUMBERS, EXPLAINED
How to use this calculator.
Open-top rectangular shell with four sides and a bottom, no lid; outside cavity corners are sharp. Geometry only, with uniform wall thickness.
Start with your inputs
Enter rectangular cavity width (mm), rectangular cavity depth (mm), rectangular cavity height (mm), uniform shell thickness (mm). Keep amounts in the units shown on each field. The example is a starting point, not a recommended value.
| Input | Example value |
|---|---|
| Rectangular cavity width (mm) | 30 |
| Rectangular cavity depth (mm) | 20 |
| Rectangular cavity height (mm) | 10 |
| Uniform shell thickness (mm) | 2 |
A worked example
With the example inputs above, outer cavity volume (ml) is 6. Change the inputs to explore your own scenario.
| Result | Example answer |
|---|---|
| Outer cavity volume (mL) | 6 |
| Filling void (mL) | 3.328 |
| Chocolate shell volume (mL) | 2.672 |
How this is calculated
Outer cavity volume (mL)
Multiply dimensions in mm and convert cubic mm to mL.
Filling void (mL)
Subtract both side walls from width/depth and bottom thickness from height.
Chocolate shell volume (mL)
Subtract inner void from outer cavity volume.
Symbols and units
- a
- Rectangular cavity width (mm)
- b
- Rectangular cavity depth (mm)
- c
- Rectangular cavity height (mm)
- d
- Uniform shell thickness (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
Open-top rectangular shell with four sides and a bottom, no lid; outside cavity corners are sharp. Geometry only, with uniform wall thickness.
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?
Outer cavity volume (mL); Filling void (mL); Chocolate shell volume (mL). 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: Open-top rectangular shell with four sides and a bottom, no lid; outside cavity corners are sharp. Geometry only, with uniform wall thickness.
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 ↗
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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