THE NUMBERS, EXPLAINED
How to use this calculator.
Units are consistent within each item; all receipts and issues should be recorded. Negative loss indicates a stock surplus.
Start with your inputs
Enter opening consumable stock by item, purchases by item, recorded issues by item, physical closing count by item, unit acquisition costs (currency). Keep amounts in the units shown on each field. The example is a starting point, not a recommended value.
| Input | Example value |
|---|---|
| Opening consumable stock by item | 100,200 |
| Purchases by item | 50,100 |
| Recorded issues by item | 120,240 |
| Physical closing count by item | 20,50 |
| Unit acquisition costs (currency) | 2,1 |
A worked example
With the example inputs above, expected closing stock by item is 30, 60. Change the inputs to explore your own scenario.
| Result | Example answer |
|---|---|
| Expected closing stock by item | 30, 60 |
| Unexplained loss by item | 10, 10 |
| Value of signed unexplained loss (currency) | 30 |
How this is calculated
Expected closing stock by item
Roll forward opening stock plus purchases less issues.
Unexplained loss by item
Compare expected stock with physical count.
Value of signed unexplained loss (currency)
Value each signed discrepancy at the supplied unit cost.
Symbols and units
- a
- Opening consumable stock by item
- b
- Purchases by item
- c
- Recorded issues by item
- d
- Physical closing count by item
- e
- Unit acquisition costs (currency)
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
Units are consistent within each item; all receipts and issues should be recorded. Negative loss indicates a stock surplus.
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?
Expected closing stock by item; Unexplained loss by item; Value of signed unexplained loss (currency). 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: Units are consistent within each item; all receipts and issues should be recorded. Negative loss indicates a stock surplus.
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 →