THE NUMBERS, EXPLAINED
How to use this calculator.
Uses measured mixed-volume yield for the selected plaster. Flat patch volume equals area times thickness; thickness in mm directly gives litres per m².
Start with your inputs
Enter terrain patch areas (m²), plaster thickness by patch (mm), measured mixed yield (l/kg dry), maximum dry batch size (kg). Keep amounts in the units shown on each field. The example is a starting point, not a recommended value.
| Input | Example value |
|---|---|
| Terrain patch areas (m²) | 0.5,1 |
| Plaster thickness by patch (mm) | 4,6 |
| Measured mixed yield (L/kg dry) | 1.25 |
| Maximum dry batch size (kg) | 2 |
A worked example
With the example inputs above, mixed plaster volume (l) is 8. Change the inputs to explore your own scenario.
| Result | Example answer |
|---|---|
| Mixed plaster volume (L) | 8 |
| Required dry plaster (kg) | 6.4 |
| Mixing batches | 4 |
How this is calculated
Mixed plaster volume (L)
Multiply each patch area by millimetre thickness and add litres.
Required dry plaster (kg)
Divide mixed volume by measured litres per dry kg.
Mixing batches
Round dry requirement divided by maximum dry batch mass up.
Symbols and units
- a
- Terrain patch areas (m²)
- b
- Plaster thickness by patch (mm)
- c
- Measured mixed yield (L/kg dry)
- d
- Maximum dry batch size (kg)
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 measured mixed-volume yield for the selected plaster. Flat patch volume equals area times thickness; thickness in mm directly gives litres per m².
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?
Mixed plaster volume (L); Required dry plaster (kg); Mixing batches. 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 measured mixed-volume yield for the selected plaster. Flat patch volume equals area times thickness; thickness in mm directly gives litres per m².
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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