The same salary, every state we can check

Why the gap is smaller than it looks

Federal income tax and FICA are the same wherever you live, and for most salaries they are the larger part of the bill. State income tax moves the number, but it moves it less than the headline rate suggests, because the federal share does not move at all.

A state with no income tax is also not a state with no taxes. Texas and New Hampshire carry unusually high property taxes, Washington has among the highest sales taxes in the country, and none of that reaches a paycheck calculator. This compares one line of the bill.

Which states are here

Only states whose tax this calculator can reproduce exactly. Each one is checked against PolicyEngine, an open-source model of all fifty states that is cross-validated against the National Bureau of Economic Research's TAXSIM, and a state is left out until every test income matches to the cent.

That is why the list is short. American state income tax is not a rate on your salary: Pennsylvania taxes gross with no deduction, Colorado starts from federal taxable income with its own additions, and Illinois works from its own base income less its own exemptions. States join this table as each one is modelled and verified, not before.