Calwarden
Back to calculator
Finance & LoansGenerated accuracy model review: 2026-05-06

Marriage Tax Calculator accuracy and testing

This page documents how Calwarden builds trust for this calculator: source notes, regression-style default tests, limitations, assumptions, unit handling, rounding, and visible change history.

Formula source

  • It calculates Federal Tax for Person A (Single) + Person B (Single). Then it sums the income and calculates Federal Tax for a Married Joint couple. The difference is the Marriage Impact.

Test cases

Default input regression check

Generated from the checked-in default inputs and calculate function.

Inputs

  • Federal Tax Table: irs_2026
  • Partner 1 Income: $60,000
  • Partner 2 Income: $50,000
  • Custom Federal Rate: 15%

Expected outputs

  • Marriage Impact: $0.00
  • Tax Filing Jointly: $8,840.00
  • Total Tax Filing Single: $8,840.00

Known limitations

  • Simplified calculation using Standard Deduction only. Does not account for itemized deductions, child credits, or other complex tax situations.

Assumptions

  • Inputs are interpreted exactly as entered in the calculator form.
  • The calculation runs locally in the browser using the current checked-in calculator definition.

Unit handling

  • Federal Tax Table accepts one of the configured options.
  • Partner 1 Income accepts values in $.
  • Partner 2 Income accepts values in $.
  • Custom Federal Rate accepts values in %.
  • Marriage Impact is displayed as currency.
  • Tax Filing Jointly is displayed as currency.
  • Total Tax Filing Single is displayed as currency.

Rounding rules

  • Number displays use up to 2 decimal places in the calculator UI.
  • Currency outputs are displayed with standard US dollar formatting.
  • Input precision follows configured step values where provided.

Version history

1.0.0 - 2026-05-06

Generated accuracy and testing page from the current marriage-tax-calculator calculator definition.

Change log

2026-05-06

Published default regression test documentation and metadata fallbacks for Marriage Tax Calculator.

Calculator transparency

Accuracy pages are generated from checked-in calculator definitions and can be upgraded with curated review metadata over time.

Use calculator