Calculator methodology

Tax-year scope: Calculator defaults use the verified year recorded in the shared tax configuration. State and local rates remain user-entered planning assumptions.

Formula and source process

Annual values are stored with source URLs, effective dates, verification status, and review notes. Shared calculation functions retain decimals while most money displays are rounded to avoid false precision.

Privacy and output scope

Calculations run locally in the browser. Inputs are not sent, stored in cookies, placed in URLs, or saved to local storage. Results are planning estimates, not returns, filings, eligibility determinations, or penalty-protection conclusions.

Corrections

A material correction should update the canonical configuration or formula, generator source, affected generated pages, tests, methodology, and review date. Official-source links must be checked during annual review.