Income Tax Calculator

Filing status selects a different bracket table entirely via getFederalBrackets -- at the lower rates, the married filing jointly bands stretch to almost twice the span of the single bands. At the default $75,000 income, switching from single to married filing jointly moves Effective Tax Rate from about 10.2% to about 6.2%, a bigger swing than a moderate income change produces, because it changes which bracket boundaries apply to the same dollar of income rather than just adding more taxed dollars.

No. Social Security (6.2% up to the 2026 wage base of $184,500) and Medicare (1.45%, plus 0.9% above $200,000) are computed directly from your gross income in this calculator with no filing-status branch at all -- FICA Taxes stays identical whether Filing Status is set to single or married filing jointly, holding gross income fixed.

Marginal Tax Rate only changes when taxable income crosses into the next bracket boundary. At the default $75,000 gross income (about $58,900 taxable after the standard deduction for a single filer), that sits well inside the 2026 22% bracket ($50,400 to $105,700), so a moderate raise or cut leaves the marginal rate unchanged, while switching filing status swaps the whole bracket table and moves it immediately.

The engine uses whichever total is larger: the amount you enter for Itemized Deductions, or the 2026 standard deduction (getStandardDeduction, $16,100 for a single filer). Leaving it at $0 simply means the standard deduction applies, since $0 in itemized deductions is always less than the standard deduction -- you only need to fill this in if your real itemized total (mortgage interest, SALT, charitable gifts) exceeds the standard amount.