Federal and state personal income tax

Federal income tax is administered by the IRS and applies wherever in the United States you live. State income tax is separate: its own rules, its own brackets, its own return, decided by the state you are a resident of.

They are calculated independently, which is why a change in your income can move the two figures by quite different amounts, and why living in a state with no income tax does not reduce your federal bill at all.

Countorra supports California, Texas, Arizona, Florida and New York. Your workspace records the state you live in, and that is what selects which state rules are used — it is read from your workspace on the server every time a figure is produced, never guessed and never taken from the page you are looking at.

Of those states, Texas and Florida levy no individual income tax, so the state figure is zero and only the federal calculation applies. California uses Form 540, Arizona uses Form 140 and New York uses Form IT-201.

Countorra calculates 2026 US individual income tax from the information you enter or confirm, using the rules the IRS and the supported states have published. California's 2026 figure follows the state's official estimated-tax method until its final rates are out. The calculation is explicit about its boundaries rather than quietly approximate.

New York figures cover New York State only — not New York City, Yonkers, or the MCTMT. California's 2026 figure uses the Franchise Tax Board's own 2026 method until its final 2026 rates are published, and Arizona's 2026 standard deduction is computed from Arizona law; each result says which rules produced it. No other state and no local tax is covered, and no non-US tax system is covered at all. Every result lists what it does not include; that list is part of the answer, not a footnote to it.