Independent Calculator

Enter a simple W-2 taxpayer scenario and see the engine's independently-calculated Federal, California, and Arizona results side by side — computed from the versioned tax_rules table, not hardcoded (plan doc §9). The engine automatically uses whichever of the standard deduction or itemized deductions (Schedule A / CA / AZ) is greater, and gives long-term capital gains federal preferential rates (0/15/20%, stacked on top of ordinary income) plus Arizona's 25% long-term-gain subtraction. Self-employment net profit gets Schedule SE tax (15.3% on 92.35% of profit, split Social Security/Medicare) as a separate tax, with half deductible above the line. Retirement distributions taken early (pre-59½) get a federal 10% penalty AND California's own separate 2.5% penalty; Arizona excludes up to $2,500 of qualifying government pension income. Deliberately narrow scope otherwise: single/MFJ only, no rental income or Social Security benefits yet, no QBI deduction.

Itemized deductions (optional) — leave at 0 to use the standard deduction

Federal SALT (state income tax + property tax) is capped at $40,000; California excludes state income tax paid to California itself; Arizona backs the state income tax portion out of the federal total. No mortgage debt cap or charitable AGI limits modeled yet.

Retirement distributions (optional) — leave at 0 if none

Early distributions get a federal 10% penalty AND a separate California 2.5% penalty — not the same tax twice, two different jurisdictions each applying their own rate. Arizona excludes up to $2,500 of qualifying government/state/local pension income (not the full military-pension exclusion, which isn't modeled yet). Social Security benefits are a different income type and aren't modeled here.