THE NUMBERS, EXPLAINED
How to use this calculator.
One consumable shared across multiple service types, with a user-selected travel reserve. Repeat with distinct products on separate worksheets.
Start with your inputs
Enter booked service counts by type, consumable units per service type, already packed consumable units, supplier pack size (units), additional travel-day reserve units. Keep amounts in the units shown on each field. The example is a starting point, not a recommended value.
| Input | Example value |
|---|---|
| Booked service counts by type | 4,2 |
| Consumable units per service type | 3,5 |
| Already packed consumable units | 15 |
| Supplier pack size (units) | 10 |
| Additional travel-day reserve units | 3 |
A worked example
With the example inputs above, booked-service consumption (units) is 22. Change the inputs to explore your own scenario.
| Result | Example answer |
|---|---|
| Booked-service consumption (units) | 22 |
| Unpacked shortage including reserve (units) | 10 |
| Packs to purchase | 1 |
How this is calculated
Booked-service consumption (units)
Multiply service counts by the supplied per-service recipe.
Unpacked shortage including reserve (units)
Add travel reserve and deduct packed stock.
Packs to purchase
Round the shortage to whole supplier packs.
Symbols and units
- a
- Booked service counts by type
- b
- Consumable units per service type
- c
- Already packed consumable units
- d
- Supplier pack size (units)
- e
- Additional travel-day reserve units
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
One consumable shared across multiple service types, with a user-selected travel reserve. Repeat with distinct products on separate worksheets.
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?
Booked-service consumption (units); Unpacked shortage including reserve (units); Packs to purchase. 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: One consumable shared across multiple service types, with a user-selected travel reserve. Repeat with distinct products on separate worksheets.
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 →