Run the numbers on the years ahead

A simulator is only useful if the rule inside it is right. We checked the popular "retirement tax by state" calculators against the actual state rules and found every one of them wrong. This site exists to do the arithmetic properly: rules taken from the IRS and each state's own department of revenue, test cases you can read, and a date on every figure.

What every tool here promises

• Primary sources only. Federal figures come from the IRS revenue procedure for the year, state figures from the state's own guide or statute. We do not copy other calculators.
• Published test cases. Each tool has a set of worked examples with the expected answer, so you can check us - and so we cannot quietly drift.
• Laws that actually passed. Before a rule goes in, we confirm the bill was enacted. A calculator we tested was applying a Colorado bill that died in committee.
• A date on every figure. Tax rules change every year; the page tells you when it was last checked.
• No advice. We show what the rules do to your numbers. What you do with that is yours to decide.

How the tools are built

Each simulator starts as a written specification of the rule, a table of the year's parameters with its source, and a reference calculation that produces the expected answers. The page you use is checked against that reference before it goes live and again whenever a parameter changes. Everything runs in your browser; nothing you type is sent to us.