THE NUMBERS, EXPLAINED
How to use this calculator.
Positive adjustments add charges and negative adjustments are credits. Expected invoice amounts must be independently established; no tariff is inferred.
Start with your inputs
Enter expected invoice totals by account (currency), issued invoice totals by account (currency), signed posted billing adjustments (currency). Keep amounts in the units shown on each field. The example is a starting point, not a recommended value.
| Input | Example value |
|---|---|
| Expected invoice totals by account (currency) | 100,200,300 |
| Issued invoice totals by account (currency) | 110,180,300 |
| Signed posted billing adjustments (currency) | -5,10,0 |
A worked example
With the example inputs above, residual billing errors by account (currency) is 5, -10, 0. Change the inputs to explore your own scenario.
| Result | Example answer |
|---|---|
| Residual billing errors by account (currency) | 5, -10, 0 |
| Residual overbilling (currency) | 5 |
| Residual underbilling (currency) | 10 |
| Net residual billing error (currency) | -5 |
How this is calculated
Residual billing errors by account (currency)
Apply signed adjustments and compare with expected invoices.
Residual overbilling (currency)
Add positive residual errors without netting underbilling.
Residual underbilling (currency)
Add absolute negative residual errors separately.
Net residual billing error (currency)
Reconcile all posted billing to all expected billing.
Symbols and units
- a
- Expected invoice totals by account (currency)
- b
- Issued invoice totals by account (currency)
- c
- Signed posted billing adjustments (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
Positive adjustments add charges and negative adjustments are credits. Expected invoice amounts must be independently established; no tariff is inferred.
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?
Residual billing errors by account (currency); Residual overbilling (currency); Residual underbilling (currency); Net residual billing error (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: Positive adjustments add charges and negative adjustments are credits. Expected invoice amounts must be independently established; no tariff is inferred.
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.
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