Accuracy & sources review

CalculatorUSA App is a finance and everyday math education site. Tools are educational worksheets — not loan approvals, tax filings, or investment advice.

• Engines are covered by unit tests for core identities (amortization, tip math, DTI, FICA orientation, and related).
• Each engine has citations in the methodology registry (IRS, CFPB, HUD, SSA, and similar public materials where applicable).
• User-entered rates (sales tax, PMI, MIP, APY) are never claimed as live statutory lookups.
• When official schedules change, defaults and notes should be updated in a content review pass.
• Report suspected errors via Contact with the page URL.

See Methodology for the full engine list and evidence tiers, and Editorial policy for publishing standards.