The short answer
Federal income tax is exact, sourced directly from the IRS’s own tax-year 2026 announcement. FICA is exact using the standard statutory rates. State tax is exact only for the 9 states with no wage income tax — everywhere else, it’s an estimate based on a rate you provide, and it’s labeled that way on purpose.
That’s the whole point of the Exact/Estimated badges on every result: nothing gets dressed up as more certain than it actually is. The other half of that trust question is what happens to the salary you type in — see Does Your Paycheck Calculator Sell Your Data? if accurate numbers aren’t the only thing you’re checking for.
Where the federal numbers come from
The 2026 federal tax brackets for Single and Married Filing Jointly filers are quoted directly from the IRS’s own tax year 2026 inflation-adjustment announcement (IR-2025-102, Revenue Procedure 2025-32) — fetched from the primary source, not paraphrased from a third-party summary. See 2026 Federal Tax Brackets: The Actual IRS Numbers for the full table across every filing status.
Head of Household brackets are the one exception worth being upfront about: that IRS press release doesn’t itemize Head of Household thresholds on its own, only a single data point (the standard deduction). This calculator uses Tax Foundation’s published transcription of the same Revenue Procedure for those brackets — a reputable secondary source, but a secondary source, not the primary IRS document itself.
Married Filing Separately isn’t published as its own table anywhere. By long-standing IRS rule, MFS brackets are exactly half of the Married Filing Jointly thresholds at every bracket — that’s a statutory rule, not something that changes year to year, so it doesn’t need fresh sourcing the way inflation-adjusted numbers do.
Where the FICA numbers come from
Social Security (6.2%) and Medicare (1.45%) rates, the $184,500 Social Security wage base, and the Additional Medicare Tax thresholds are corroborated across multiple independent sources. One honest caveat: they haven’t been independently cross-checked against ssa.gov directly for this tax year, since a direct fetch attempt returned an access error. If you’re making a decision where this specific number really matters, it’s worth a quick manual check against ssa.gov yourself.
That’s a more specific and more useful answer than “trust us” — and it’s the same standard applied throughout this site: state exactly how confident a number is, not just whether it’s shown.
Check the math yourself
Take a $75,000 single-filer salary as an example:
- Standard deduction (2026, single): $16,100
- Taxable income: $75,000 − $16,100 = $58,900
- Tax: 10% of the first $12,400, 12% of the next $38,000 (up to $50,400), 22% of the remaining $8,500 → $1,240 + $4,560 + $1,870 = $7,670
- FICA: 6.2% Social Security + 1.45% Medicare = 7.65% of $75,000 = $5,737.50
Run the same salary through the calculator above and the federal and FICA figures should match. If they don’t, that’s worth reporting — see Contact.
What “Estimated” means in practice
For every state except the 9 with no wage income tax, this calculator asks for an effective rate rather than presenting a canned 50-state table as fact. State income tax law is genuinely complex — brackets, credits, local add-ons — and a flat per-state number would be either wrong for most people or would require modeling every state’s tax code in full. Neither is worth pretending to have solved with a single “Estimated” label doing all the work. See The 9 States With No Income Tax if you want to check whether you’re one of the states where state tax is Exact instead.