Methodology & data sources
StateTakeHome is a data house, not a tax advisory firm. Our promise is simple: every rate, bracket, wage base and deduction used by our calculators comes from an official government source, carries an explicit tax-year vintage, and is re-verified when the source publishes an update. This page documents exactly where our numbers come from and how the calculators use them.
Primary sources
- Federal withholding & brackets (2026): IRS Rev. Proc. 2025-32 and IRS Publication 15-T — brackets, standard deductions, and the OBBBA Schedule 1-A deduction rules (tips, overtime, car-loan interest, senior deduction).
- Social Security & Medicare (FICA): SSA Contribution & Benefit Base — the 2026 wage base and the Additional Medicare thresholds.
- State income tax (50 states + DC):each state's Department of Revenue publication, verified state by state. Every state calculator page links to its own DOR source. Where 2026 legislation changed rates mid-cycle (e.g. Georgia H.B. 111, South Carolina H.4216, West Virginia's phased reduction), we use the enacted 2026 values, not the prior year's.
- State payroll extras: SDI/PFML programs (e.g. California SDI at 1.3% with no wage cap since SB 951), SUI employee shares, and local/occupational taxes, from the relevant state agency publications.
- Cost of living: BEA Regional Price Parities for state-adjusted purchasing power.
- Wages & property data: BLS OES for wage benchmarks and Census ACS (2024 5-year) for median home values and effective property-tax rates across 3,100+ counties.
- Canada (/ca): CRA federal brackets, all 13 provincial/territorial schedules, CPP/EI, and Québec-specific RRQ/RQAP with the federal abatement, from CRA and Revenu Québec publications.
How the calculators work
The engine is a set of deterministic, jurisdiction-agnostic functions. Each jurisdiction is a data file (brackets, standard deduction, filing-status rules, FICA/extras), so a calculation is fully reproducible: gross pay → pre-tax adjustments → federal withholding (Pub 15-T method) → FICA (Social Security to the wage base, Medicare plus the 0.9% additional rate where it applies) → state tax (none / flat / progressive, with state standard deductions) → state extras (SDI, PFML, local taxes) → net pay. OBBBA Schedule 1-A deductions (tips, overtime) are modeled with their per-return caps and MAGI phase-outs. All computation runs in your browser — the numbers you type are never sent to our servers.
Every state page also publishes its result set as structured data (Dataset JSON-LD and a machine-readable AI-retrieval layer), so researchers and journalists can cite exact figures rather than re-deriving them.
Verification & update policy
- Explicit vintage:every figure is labeled with its tax year. We never present a prior year's number as current.
- Engine ↔ content reconciliation: when a fact-check changes a published rate, the calculator data is corrected in the same change — the prose and the math cannot disagree.
- Review cadence: federal figures are re-checked against IRS releases each fall; state figures when the DOR publishes changes; every page shows its last-reviewed date.
- Corrections:if you spot a figure that doesn't match its official source, tell us — verified corrections ship within 48 hours.
What we are — and what we are not
Our team does research, data analysis and market study. We are not CPAs, EAs or tax attorneys, and we do not claim professional review of your personal situation. StateTakeHome provides estimates for informational purposes only; your actual paycheck depends on your W-4 elections, local taxes, benefits and other factors. For advice on your specific situation, consult a licensed professional.