THE NUMBERS, EXPLAINED
How to use this calculator.
Volume-only procurement model. Supplier calendar limits and measured water-quality conditions can require earlier replacement.
Start with your inputs
Enter metered brew-water use (l/day), supplier rated cartridge capacity (l), cartridge purchase cost (currency), planned operating days. Keep amounts in the units shown on each field. The example is a starting point, not a recommended value.
| Input | Example value |
|---|---|
| Metered brew-water use (L/day) | 200 |
| Supplier rated cartridge capacity (L) | 10000 |
| Cartridge purchase cost (currency) | 100 |
| Planned operating days | 120 |
A worked example
With the example inputs above, volume-based interval (days) is 50. Change the inputs to explore your own scenario.
| Result | Example answer |
|---|---|
| Volume-based interval (days) | 50 |
| Cartridges needed from empty inventory | 3 |
| Treatment consumable cost (currency/L) | 0.01 |
How this is calculated
Volume-based interval (days)
Divide supplied rated capacity by daily water use.
Cartridges needed from empty inventory
Round up total volume divided by cartridge capacity.
Treatment consumable cost (currency/L)
Spread cartridge price over its rated volume.
Symbols and units
- a
- Metered brew-water use (L/day)
- b
- Supplier rated cartridge capacity (L)
- c
- Cartridge purchase cost (currency)
- d
- Planned operating days
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
Volume-only procurement model. Supplier calendar limits and measured water-quality conditions can require earlier replacement.
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?
Volume-based interval (days); Cartridges needed from empty inventory; Treatment consumable cost (currency/L). 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: Volume-only procurement model. Supplier calendar limits and measured water-quality conditions can require earlier replacement.
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.
Read the quality report →