An independent tax calculator website you can inspect.
TaxMathKit is an independent website of browser-based tax calculators maintained by Saigetsu233. Each tool shows its formula, tax year, assumptions, exclusions, and links to primary government sources.
TaxMathKit refers to this site at taxmathkit.com and its open formula project. It is not a tax authority, filing service, accounting firm, or product from another company with a similar name.
What the project does
It turns published schedules and rules into transparent planning calculators for federal income tax, 1099 and self-employment income, sales tax, capital gains, quarterly payments, vehicle tax, and VAT.
How it is maintained
Saigetsu233 reviews source links, separates tax years, tests core formulas, and records material changes in the public version log. Calculator inputs stay in the browser and are not intentionally sent to TaxMathKit analytics.
Open formula source
The corresponding formula library is public on GitHub. The repository includes examples, tests, and citation guidance.