THE NUMBERS, EXPLAINED
How to use this calculator.
Inventory arithmetic only; daily portion must be supplied independently. Starts with a full pack and constant consumption, with day zero as today.
Start with your inputs
Enter food pack mass (g), owner-supplied daily portion per pet (g), pets using this pack, order lead time (days). Keep amounts in the units shown on each field. The example is a starting point, not a recommended value.
| Input | Example value |
|---|---|
| Food pack mass (g) | 2000 |
| Owner-supplied daily portion per pet (g) | 100 |
| Pets using this pack | 2 |
| Order lead time (days) | 3 |
A worked example
With the example inputs above, pack duration (days) is 10. Change the inputs to explore your own scenario.
| Result | Example answer |
|---|---|
| Pack duration (days) | 10 |
| Latest reorder day from start | 7 |
| Food used during lead time (g) | 600 |
How this is calculated
Pack duration (days)
Divide pack mass by combined supplied daily portions.
Latest reorder day from start
Subtract delivery lead time from depletion day, floored at zero.
Food used during lead time (g)
Multiply combined daily use by order lead time.
Symbols and units
- a
- Food pack mass (g)
- b
- Owner-supplied daily portion per pet (g)
- c
- Pets using this pack
- d
- Order lead time (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
Inventory arithmetic only; daily portion must be supplied independently. Starts with a full pack and constant consumption, with day zero as today.
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?
Pack duration (days); Latest reorder day from start; Food used during lead time (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: Inventory arithmetic only; daily portion must be supplied independently. Starts with a full pack and constant consumption, with day zero as today.
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: Solve proportions and their applications ↗
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 →