Evidence
Sources and update record
Formula stability does not remove the need to verify timing, function behavior, definition variants and numerical boundaries.
Sources checked 2026-08-17. These references support model definition and spreadsheet behavior. They do not validate a reader’s inputs or turn a model into a recommendation.
Investor.gov Compound Interest CalculatorU.S. Securities and Exchange Commission · principal, contribution, term, rate, variance and compounding input expectationsCalculate NPV and IRR in ExcelMicrosoft · periodic versus dated cash-flow function selectionNPV functionMicrosoft · periodic NPV timing and initial cash-flow treatmentIRR functionMicrosoft · periodic IRR input and iterative behaviorXNPV functionMicrosoft · dated cash flows and actual-date discountingXIRR functionMicrosoft · dated cash-flow return and convergence behaviorMIRR functionMicrosoft · separate finance and reinvestment ratesGoogle Sheets NPVGoogle · spreadsheet NPV syntax and periodic cash-flow behaviorGoogle Sheets IRRGoogle · spreadsheet IRR syntax and periodic inputsFinancial definitionsNYU Stern School of Business · definition variants and context for financial measuresBreak-even pointU.S. Small Business Administration · break-even units, sales dollars, contribution margin and business-planning inputsCalculate a Break-Even Point in Units and DollarsOpenStax, Rice University · cost-volume-profit relationships, contribution margin, break-even sales and target-profit calculationsBeginners’ Guide to Financial StatementsU.S. Securities and Exchange Commission · income statement, balance sheet, cash-flow statement and common financial-ratio relationshipsIAS 16 Property, Plant and EquipmentIFRS Foundation · depreciable amount, useful life, residual value and systematic depreciation principles
Update triggers
Spreadsheet-function behavior and regulated guidance are rechecked before a related model is published. Stable arithmetic is retested whenever the engine changes. Ratio definitions are reviewed with the source and named reviewer for the chosen accounting basis.