Legal & Policies

Tax Formula Verification

24 of the 24 published tax calculators have an automated formula test suite. Each row gives one calculator's passing cases and the kinds of check behind them.

Last updated 16 September 2026

This is the tax section of the formula verification report, which explains what each kind of case tests, how the counts are produced and what they do not prove. Rows run from the largest suite to the smallest; each row's address ends in the calculator's slug, so one calculator's evidence can be linked and cited on its own. The test file behind every row, and the per-kind numbers, are in the machine-readable report.

Every tax calculator, with its case mix

Automated formula-test coverage for the Tax calculators: passing cases and case mix per calculator
CalculatorCasesCase mix
Average Cost Basis Calculator6,73068 independent · 19 golden · 18 boundary · 6,600 property · 25 structural
Indexation Calculator6,73068 independent · 19 golden · 18 boundary · 6,600 property · 25 structural
Canada GST HST PST Calculator5,14464 independent · 31 golden · 15 boundary · 5,000 property · 34 structural
Contractor TDS Calculator5,14464 independent · 31 golden · 15 boundary · 5,000 property · 34 structural
India GST Calculator5,14464 independent · 31 golden · 15 boundary · 5,000 property · 34 structural
Salary TDS Calculator5,14464 independent · 31 golden · 15 boundary · 5,000 property · 34 structural
UK VAT Calculator5,14464 independent · 31 golden · 15 boundary · 5,000 property · 34 structural
Salary & Take-Home Pay Calculator26251 golden · 22 boundary · 151 property · 38 structural
Income Tax Calculator1608 independent · 68 golden · 44 boundary · 20 property · 20 structural
VAT/GST Calculator14535 golden · 53 boundary · 16 property · 41 structural
Capital Gains Tax Calculator7917 independent · 20 golden · 14 boundary · 12 property · 16 structural
Self-Employment Tax Calculator7917 independent · 20 golden · 14 boundary · 12 property · 16 structural
Bonus Tax Calculator6816 golden · 7 boundary · 9 property · 36 structural
Estimated Tax Payment Calculator6816 golden · 7 boundary · 9 property · 36 structural
Overtime Tax Calculator6816 golden · 7 boundary · 9 property · 36 structural
Payroll Tax Calculator6816 golden · 7 boundary · 9 property · 36 structural
Tax Refund Calculator6816 golden · 7 boundary · 9 property · 36 structural
Corporate Tax Calculator4611 golden · 5 boundary · 6 property · 24 structural
Dividend Tax Calculator4611 golden · 5 boundary · 6 property · 24 structural
Quarterly Tax Calculator4611 golden · 5 boundary · 6 property · 24 structural
Effective Tax Rate Calculator442 independent · 8 golden · 6 boundary · 4 property · 24 structural
Taxable Income Calculator442 independent · 8 golden · 6 boundary · 4 property · 24 structural
Sales Tax Calculator238 golden · 10 boundary · 3 property · 2 structural
Global Import Duty Calculator2015 golden · 4 boundary · 1 structural
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Questions about this policy?Published by Calculator Matters (calculatormatters.com). Last reviewed 16 September 2026. Created and maintained by Jay Sudha (about Calculator Matters). These pages are reviewed regularly, and questions are always welcome.
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