THE NUMBERS, EXPLAINED
How to use this calculator.
Mass audit of comparable served and returned food; estimated wasted food cost is proportional to mass and excludes plate, packaging and inedible components.
Start with your inputs
Enter served food mass by menu item (kg), returned uneaten mass by item (kg), food cost by item (currency/kg). Keep amounts in the units shown on each field. The example is a starting point, not a recommended value.
| Input | Example value |
|---|---|
| Served food mass by menu item (kg) | 10,8 |
| Returned uneaten mass by item (kg) | 2,1 |
| Food cost by item (currency/kg) | 5,10 |
A worked example
With the example inputs above, returned waste by item (%) is 20, 12.5. Change the inputs to explore your own scenario.
| Result | Example answer |
|---|---|
| Returned waste by item (%) | 20, 12.5 |
| Waste ingredient cost by item | 10, 10 |
| Total returned waste cost | 20 |
How this is calculated
Returned waste by item (%)
Divide returned uneaten mass by served mass for each item.
Waste ingredient cost by item
Multiply each returned mass by its food cost per kilogram.
Total returned waste cost
Add estimated returned food cost across menu items.
Symbols and units
- a
- Served food mass by menu item (kg)
- b
- Returned uneaten mass by item (kg)
- c
- Food cost by item (currency/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
Mass audit of comparable served and returned food; estimated wasted food cost is proportional to mass and excludes plate, packaging and inedible components.
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?
Returned waste by item (%); Waste ingredient cost by item; Total returned waste cost. 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: Mass audit of comparable served and returned food; estimated wasted food cost is proportional to mass and excludes plate, packaging and inedible components.
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.
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