THE NUMBERS, EXPLAINED
How to use this calculator.
Bills each unit for its own meter plus an equal share of verified common use. Unexplained volume is reported separately and not charged automatically.
Start with your inputs
Enter building metered volume (m³), unit metered volumes (m³), verified common-use volume (m³), unit water price (currency/m³). Keep amounts in the units shown on each field. The example is a starting point, not a recommended value.
| Input | Example value |
|---|---|
| Building metered volume (m³) | 100 |
| Unit metered volumes (m³) | 30,50 |
| Verified common-use volume (m³) | 10 |
| Unit water price (currency/m³) | 2 |
A worked example
With the example inputs above, unexplained meter difference (m³) is 10. Change the inputs to explore your own scenario.
| Result | Example answer |
|---|---|
| Unexplained meter difference (m³) | 10 |
| Unit charges | 70, 110 |
| Unallocated difference value | 20 |
How this is calculated
Unexplained meter difference (m³)
Subtract unit readings and verified common use from building volume.
Unit charges
Add equal common-use volume to each unit reading and apply rate.
Unallocated difference value
Value the signed unexplained difference at supplied rate.
Symbols and units
- a
- Building metered volume (m³)
- b
- Unit metered volumes (m³)
- c
- Verified common-use volume (m³)
- d
- Unit water price (currency/m³)
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
Bills each unit for its own meter plus an equal share of verified common use. Unexplained volume is reported separately and not charged automatically.
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?
Unexplained meter difference (m³); Unit charges; Unallocated difference value. 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: Bills each unit for its own meter plus an equal share of verified common use. Unexplained volume is reported separately and not charged automatically.
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 →