Purchase and yield
Usable quantity equals purchase quantity multiplied by usable yield. Usable unit cost equals purchase cost divided by usable quantity.
Contribution margin
Contribution equals net sales minus the costs that change with the sale. Percentage fees are calculated on the entered net selling price.
Tax
Collected sales tax or VAT is excluded from net revenue. No jurisdiction-specific rate is supplied unless supported by a maintained official source.
Precision
Calculations retain full precision internally. Currency values are rounded only for display.
Evidence labels
User input, estimate, official, observed, measured, and verified records remain distinct. An estimate is never represented as a measurement.
Versioning and corrections
Material methodology changes receive a version and effective date. Calculation or editorial issues can be reported through the contact page.