Methodology

What we cover

These counts are computed from the rate tables when this page is built, not written by hand — so they cannot fall out of step with the data. Browse any of it on the tax tables pages.

Each table also lists the documents its figures came from, and rates each one by what published it — the enacted law and the revenue agency's own schedules rank above a press release, which ranks above a third-party summary. See how we rate sources for the full rubric.

Final vs. provisional

Every jurisdiction-year carries a status. We publish the distinction rather than smoothing it over, because the difference matters when you are relying on a number.

• Final means the figure comes from the revenue department's own published schedule for that tax year.
• Provisional means one of two things: the legislature has enacted a change but the revenue department has not yet published its tables, or no distinct figure has been published for that year and the prior year's structure carries forward. Provisional figures are directional. They are usually right, and they are not yet confirmed by the primary source.

Arkansas is a good illustration for 2026: its top rate of 3.7% comes from enacted legislation retroactive to 1 January 2026, but the state's own 2026 tables are still pending — so we mark it provisional and say why.

What the calculator models

• Federal ordinary income brackets and long-term capital gains brackets
• State personal income tax brackets for all 51 jurisdictions
• State capital gains treatment where it departs from ordinary rates — exclusions, preferential schedules, alternative maximum rates, and outright exemption
• Standard deductions, personal exemptions, tiered exemptions, and exemption credits where a jurisdiction applies them
• Federal and state corporate rates, simplified to a flat treatment

What it does not model

This is the more useful list. TaxMath is a comparison tool, not a tax-preparation engine, and these omissions are deliberate:

• Filing status. Bracket modeling is single-filer. Married, head of household, and separate filings are not yet supported.
• Payroll taxes. Social Security, Medicare, and state disability or paid-leave premiums are excluded. For some states this is a large omission — a California wage earner at $150,000 pays roughly $1,800–$1,950 a year in state disability insurance alone, on every wage dollar.
• Local income taxes. New York City, Yonkers, and the many local income taxes in Ohio, Pennsylvania, Maryland, and elsewhere are not included.
• Sales, property, excise, and business taxes. An income tax comparison is not a total tax burden comparison, and we try never to present one as the other.
• Most credits, phase-outs, AMT, and the Net Investment Income Tax.
• Withholding. What your employer withholds is not what you owe. Several states deliberately build a markup into their withholding tables.

How we handle being wrong

We publish corrections with dates on the corrections page. A publisher whose corrections log is empty is not careful — it is not checking.

In 2026 an internal review examined all 51 jurisdictions against primary sources, producing 529 adjudicated findings. Its corrections have been applied to the rate tables and to the articles on this site, and the material ones are listed on the corrections page.

This is not tax advice

TaxMath is an estimation and comparison tool for directional decisions. It is not a substitute for a tax professional, and it should not be used to prepare a return.