Tax Calculator
Your full federal and state return, computed line by line from the tax code. Enter your income and household, and see your real marginal rate — the rate on your next dollar once FICA, state tax, and every credit phase-out are stacked on top of the bracket.
Why Your Real Rate Isn’t Your Bracket
A bracket table answers one narrow question: which federal ordinary-income bracket your last dollar of taxable income lands in. It is silent about almost everything else that moves when you earn one more dollar.
FICA adds 7.65% on wages up to the Social Security wage base, then 1.45% above it, plus the 0.9% additional Medicare tax past the threshold. State income tax stacks on top in 41 states and DC, with its own brackets, deductions and credits.
Phase-outs are the part almost nobody accounts for. As income rises you can lose the Earned Income Tax Credit, the Child Tax Credit, the Saver’s Credit, IRA deductibility, and ACA premium tax credits — each withdrawal behaving exactly like an extra tax on the income that caused it. Cross an IRMAA threshold and Medicare premiums step up for the whole year on the strength of one dollar.
The result is a marginal rate that can sit far above the bracket you would read off a table, and in the Earned Income Tax Credit’s phase-in range, below zero. This calculator measures the rate rather than looking it up: it computes your whole return, adds a dollar, and computes it again.