Limitations

Not modeled at all

• Tax credits and phaseouts (Child Tax Credit, EITC, etc.)
• Itemized deductions — we use the standard deduction only
• Alternative Minimum Tax (AMT)
• Capital gains tax
• Self-employment tax
• Nonresident income allocation between states that have no reciprocity agreement — where two states both tax the wages and the home state gives a credit, we do not compute that credit. State pairs that do have an agreement are modeled; see reciprocity.
• Dependents or household size adjustments
• Markets outside the United States

Filing status accuracy

Single and married-filing-jointly are the two statuses we've verified state by state. Every state's joint-filer brackets were individually checked against published sources in August 2026.

• Head of household and married-filing-separately are not fully verified. For most states we apply the single-filer brackets to these statuses, because no source we could access publishes distinct schedules for them. Head-of-household brackets are generally wider than single, so where they differ, this site overstates your tax rather than understating it.
• California specifically: its head-of-household schedule is real and differs from single, but the state's own rate-schedule page blocks automated access and the secondary sources we found disagreed with each other. Rather than pick one, we left it flagged.
• Two states give relief as a tax credit rather than a deduction, and we do not model it — Ohio and Utah. Both cut the tax itself instead of the income it is charged on, so we tax from the first dollar and the figure you see is too high. Ohio's credit is worth $20 per exemption. Utah's is a percentage that shrinks as income rises, and for a single filer earning much above $87,000 it is already gone.
• Eight states give a personal exemption, and we now model it — Connecticut, Illinois, Indiana, Maryland, Massachusetts, Michigan, New Jersey and West Virginia. Until September 2026 we did not, and every one of those states was charged too much. Michigan was the worst case: about $251 a year on a $75,000 salary. Maryland was the one nobody had listed, because it has a standard deduction too, so the missing exemption did not look like a gap. We found it by checking our figures against each state's own withholding calculator. The same check showed Massachusetts lets you deduct up to $2,000 of Social Security and Medicare tax, which we now include as well. If you compared us against your own return before then and we came out high, this is likely why. What we still leave out is the extra exemptions that depend on your circumstances — dependants, being 65 or over, blindness — so for those filers the figure remains a little high.
• Sixteen states show a $0 standard deduction in our data, and most of them are right. Six start from federal taxable income, where the federal deduction has already come off. Pennsylvania genuinely gives neither. Seven of the sixteen are exemption states from the list above and now carry it, which leaves Ohio and Utah as the only real gap.
• Where a state uses a sliding-scale deduction that phases out with income (Wisconsin, Rhode Island), we don't model the phaseout.

Modeled with a documented simplification

• Local and municipal income tax is modeled for New York City, Philadelphia and the rest of Pennsylvania's municipalities, Ohio's municipalities, Maryland's counties, Michigan's cities, Indiana's counties, Kentucky's occupational taxes, Missouri's earnings tax, Iowa's school district surtaxes and Wilmington, Delaware. Localities outside that list are not modeled, and where a locality's rate depends on where you work as well as where you live we model the rule for Pennsylvania and Ohio only
• Sales tax is selectable by county where we hold county data, but not to ZIP-level precision — a single county can contain several district rates, and we apply the county figure to all of them
• Real estate transfer tax is verified for all 51 jurisdictions, each against its own statute. We quote it at one reference house price rather than recalculating it from the price you type, and for the states that charge on a sliding scale that is an approximation. Vehicle fees — dealer documentation and registration — are thinner: we hold them for about 30 states, and the rest show an error rather than a guess.
• PMI, mortgage points, and adjustable-rate mortgages are not modeled for home purchase
• Resort fees and other property-specific hotel charges are not modeled
• Opportunity cost and multi-year depreciation/appreciation figures are forecasts — genuinely uncertain by nature, not a precision gap
• Some categories (cannabis, concert tickets, streaming, gym memberships, and others with real per-state taxability variance) model the majority treatment with specific documented state exceptions in their own assumptions, rather than a full 51-state rule set

Data freshness

Tax brackets and rates are current for the 2026 tax year as of this site's last data update. Federal brackets and FICA figures are re-verified annually each fall when the IRS publishes the next year's numbers; a stale dataset is a bug, not a policy — if you spot one, use the "report an error" option (coming soon) or check the as-of date shown for each figure.