How the numbers are calculated

Everything on this site is computed by one open tax engine running in your browser; the numbers printed on each page were produced by the same engine at build time. No figure is typed by hand.

United States (2026)

1. Gross pay is annualized: hourly × hours × 52 (+ overtime × multiplier), monthly × 12, bi-weekly × 26, and so on.
2. Pre-tax deductions. 401(k)/403(b) reduce federal and state taxable wages (limit $24,500, +$8,000 at 50+). HSA (limits $4,400 / $8,750) and Section 125 health premiums reduce FICA wages too.
3. Federal income tax: taxable wages minus the standard deduction ($16,100 single, $32,200 married filing jointly, $24,150 head of household) through the 2026 brackets: 10%, 12%, 22%, 24%, 32%, 35%, 37%. Source: IRS Rev. Proc. 2025-32 and Publication 15-T.
4. FICA: Social Security 6.2% up to $184,500 (SSA 2026 wage base); Medicare 1.45% plus 0.9% Additional Medicare Tax over $200,000.
5. State income tax: each state's brackets, standard deduction, personal exemptions/credits and, where allowed (Alabama, Missouri, Oregon), the federal tax deduction. Special rules are modelled for Connecticut's exemption phase-out, Maryland's percentage deduction and exemption phase-out, Wisconsin's sliding deduction, Utah's taxpayer credit, Ohio's income-based exemption and California's mental-health tax.
6. Local taxes: New York City and Yonkers, Philadelphia and other Pennsylvania EIT municipalities, Ohio cities, Michigan cities, Maryland counties, Indiana counties, Kentucky, Missouri, Delaware, Alabama and Portland metro taxes, plus a custom-rate field for anything else.
7. State payroll programs employees pay: CA SDI, NJ UI/SDI/FLI, NY PFL/SDI, MA PFML, CT Paid Leave, CO FAMLI, OR Paid Leave and transit tax, WA Paid Leave and WA Cares, RI TDI, HI TDI, MN Paid Leave, PA UC.
8. Bonus: 22% federal supplemental withholding (37% above $1M), FICA, and state supplemental rates (CA 10.23%, NY 11.7%; elsewhere the marginal rate).

The result is standard withholding for an employee with a 2020-or-later W-4 and no adjustments, which for wage-only earners taking the standard deduction equals the annual tax liability. Credits (child tax credit, EITC), itemized deductions, other income and older W-4 forms are not modelled.

State table status

States publish inflation-indexed tables at different times. The column below shows which year's official table each state currently uses; it is updated as each state releases its 2026 figures.

Verification

A reference file of test cases (federal-only, each state type, locals, pre-tax deductions, and one case per country) is checked against the engine on every build, and spot-checked against two independent published calculators per country. The build fails if any reference case drifts.

Other countries

UK: 2026/27 income tax (England/Wales/NI and Scottish bands), Class 1 NI, student loan plans 1/2/4/5/postgraduate, pension. Canada: 2026 federal and provincial brackets, basic personal amounts, CPP/CPP2/QPP, EI/QPIP, Ontario surtax and health premium. Australia: 2026–27 resident rates, LITO, Medicare levy, HELP repayment. India: FY 2026–27 new and old regime, Section 87A rebate, surcharge, cess, EPF, professional tax. Germany: 2026 Einkommensteuertarif, Steuerklassen I–VI, Soli, Kirchensteuer and social insurance.