Methodology & Data Sources

What the Calculator Computes

The PlainSalary calculator estimates US federal income tax, state income tax, and FICA / SECA payroll tax for tax year 2026. Inputs: gross annual income, filing status (single, married jointly, married separately, head of household), and US state. Outputs: federal income tax, state income tax, FICA, total tax, take-home pay, effective rate, federal marginal rate, state marginal rate, and combined top marginal rate.

Populations and vintages

Three clocks appear in this project and must not be conflated: (1) the tax year 2026 schedules the calculator applies (brackets effective for income earned in calendar 2026); (2) the source publication dates for those schedules (IRS Revenue Procedure 2025-32 in October 2025, SSA COLA fact sheet in October 2025, Tax Foundation / state DOR cross-check through February 2026), and Schema.org dateModified on dataset pages uses the newest of these; (3) the ETL load timestamp when we rebuilt the SQLite database (sitemap lastmod only). Citing the ETL day as the claims vintage is a dual-window error.

Data Sources

Every figure below is sourced directly from a primary US government publication, not a secondary compilation:

Federal Income Tax Brackets

IRS Revenue Procedure 2025-32, the agency's official notice of 2026 inflation adjustments, was published October 2025. It supplies the seven marginal brackets across all four filing statuses, plus the 2026 standard deduction, AMT exemption amounts, and long-term capital gains thresholds we apply here. Source URL: irs.gov/pub/irs-drop/rp-25-32.pdf.
Source: IRS Revenue Procedure 2025-32, 2026 federal inflation adjustments.

State Income Tax Brackets and Rates

State brackets come straight from each state's own Department of Revenue. Every 2026 rate we use (effective January 1, 2026) was checked against that state's official DOR notice directly, then cross-referenced a second time against the Tax Foundation's State Individual Income Tax Rates and Brackets, 2026 aggregator (taxfoundation.org), which covers all 50 states plus DC.
Source: State Departments of Revenue 2026 personal-income-tax publications, cross-checked against Tax Foundation State Individual Income Tax Rates and Brackets 2026.

FICA / Medicare

The 2026 Social Security wage base ($184,500) and its rates are published in the SSA's Fact Sheet 2026 Social Security Changes (ssa.gov). Unlike the brackets above, the Additional Medicare surcharge thresholds ($200,000 single / $250,000 married jointly) have been fixed by statute since 2013 and are never inflation-indexed.
Source: SSA Fact Sheet 2026 Social Security Changes; Internal Revenue Code §1411 (Affordable Care Act 2010).

Computation Pipeline

Every calculation happens client-side in the visitor's own browser; no input data ever reaches our servers. Here is the order of operations:

1. Apply standard deduction (if user opts in). Gross income minus standard deduction = taxable income.
2. Federal income tax. Walk the 2026 marginal brackets for the chosen filing status. For each bracket where taxable income exceeds the bracket low, compute (min(taxable, bracket_high) − bracket_low) × marginal_rate. Sum all bracket contributions.
3. State income tax. For states with detailed bracket schedules in our database (CA, NY, MA, NJ, IL, PA, GA, CO, NC), apply the same progressive walk algorithm. For other progressive states, approximate with the top marginal rate × taxable income (an upper-bound, see "Limitations" below). For flat-tax states, multiply taxable income by the flat rate. For no-income-tax states, state tax = 0.
4. FICA / SECA. Social Security: min(gross_wage, 184500) × 6.2% (employee) or 12.4% (self-employed). Medicare: gross_wage × 1.45% (employee) or 2.9% (self-employed). Additional Medicare: max(0, gross_wage − threshold) × 0.9%. Sum.
5. Total tax. Federal + state + FICA. Take-home. Gross minus total tax. Effective rate. Total tax ÷ gross.

Worked example: $80,000 single filer, California, standard deduction

A full worked walkthrough of the algorithm, bracket by bracket:

1. Taxable income: $80,000 − $16,100 standard deduction = $63,900.
2. Federal tax (2026 single brackets, walking each tier in order):
   • $12,400 × 10% = $1,240.00
   • ($50,400 − $12,400) × 12% = $38,000 × 12% = $4,560.00
   • ($63,900 − $50,400) × 22% = $13,500 × 22% = $2,970.00
   • Total federal = $8,770.00
3. California state tax (2026 single, walking the progressive bracket schedule on $63,900 taxable): roughly $2,496 with the standard CA progressive brackets.
4. FICA on $80,000 gross wages: Social Security $80,000 × 6.2% = $4,960; Medicare $80,000 × 1.45% = $1,160; total $6,120.
5. Total tax: $8,770 + $2,496 + $6,120 = $17,386. Take-home: $80,000 − $17,386 = $62,614. Effective rate: 21.73% on gross.

The marginal rate for the next dollar of income at this tier is 22% federal + the CA bracket rate at $63.9K. Punch the same inputs into the calculator to verify (figures match within $1 rounding).

Corpus placement (#N of M)

Every state profile states where that jurisdiction sits in PlainSalary's own 51-jurisdiction corpus. Placement is computed with SQL ROW_NUMBER over the same rows the detail pages render - never hand-picked and never invented as a quality score.

• $100K state income-tax burden - rank among all 51 jurisdictions by computed state income-tax dollars on a single filer earning $100,000 (standard deduction, wage income only), lowest burden first. No-income-tax states sit near #1; this measures the state line only, not a judgment that lower is always better for a household.
• Statutory top marginal rate - rank among wage-taxing jurisdictions only (has_income_tax = 1), highest published top rate first. Effective $100K burden and headline top rate often diverge (a high top rate with late brackets can sit below another state on dollars owed at $100K).

The Callout on each state page names the applicable signals and links here so the derivation stays visible.

Pay Competitiveness Score

Every state profile carries a 0-100 + letter-grade composite score: how competitive that jurisdiction's take-home pay and rate ceiling are against PlainSalary's own 51-jurisdiction corpus for the 2026 tax year. It is comparative arithmetic over four dimensions, not personalized tax advice.

• $50K take-home (weight 20%) - single-filer take-home pay on $50,000 gross, higher is more competitive.
• $100K take-home (weight 35%) - single-filer take-home pay on $100,000 gross, this site's own headline income level, higher is more competitive.
• $200K take-home (weight 20%) - single-filer take-home pay on $200,000 gross, higher is more competitive.
• Rate ceiling (weight 25%) - the statutory top marginal rate, lower is more competitive; the nine no-income-tax states score a rate of 0%, the best possible value on this dimension.

Each dimension is scored by linear interpolation between empirical percentile breakpoints (p10/p25/p50/p75/p90) computed once over all 51 state_burden rows for the 2026 tax year, themselves derived from the same federal and state sources used everywhere else on this site: IRS Revenue Procedure 2025-32 (federal brackets and standard deduction), the SSA FICA schedule, and each state's own Department of Revenue schedule (via the Tax Foundation compilation). A dimension with no input (none currently occur on this corpus) drops out and its weight redistributes across the remaining dimensions, so a missing figure never silently deflates the score.

Values below p10 or above p90 extrapolate linearly from the nearest two breakpoints rather than clipping, then clamp to the 0-100 range. Scores are recomputed on every request from the state's own row; the benchmark table itself is refreshed when the underlying tax-year data updates.

Limitations

The estimate covers federal, state, and FICA/SECA against gross income and the standard deduction only. It does not account for:

• Itemized deductions beyond the standard deduction - mortgage interest, state and local taxes (SALT, capped at $40,000 for 2025-2029), charitable contributions, large medical expenses
• Above-the-line adjustments - traditional IRA, HSA, student loan interest, half-SECA deduction, self-employed health insurance
• Tax credits - Child Tax Credit (refundable up to $1,700/child in 2026), Earned Income Tax Credit, Child & Dependent Care Credit, education credits (American Opportunity, Lifetime Learning), foreign tax credit, residential energy credits
• Alternative Minimum Tax (AMT) - narrowly applies after 2017 TCJA but still relevant for ISO exercisers and very-high-income filers
• Capital gains preferential rates - long-term gains taxed at 0%, 15%, 20% federal plus 3.8% NIIT above $200K/$250K thresholds
• State-specific deductions and credits - varies by state
• Local income taxes - NYC city tax (3-3.876%), some Pennsylvania municipalities, several Indiana and Maryland counties, school-district income taxes in Ohio
• For states without detailed brackets in our DB (19 progressive states beyond the 9 with detailed schedules), we approximate with the top marginal rate, which over-states tax at lower incomes. Use the per-state page for the precise schedule.

Update Schedule

• Federal brackets: refreshed within 2 weeks of each year's IRS Revenue Procedure publication (typically mid-November)
• FICA wage base: refreshed within 2 weeks of SSA October announcement
• State brackets: refreshed through Q4 of the preceding year for January-1 effective changes; mid-year changes (rare) refreshed within 2 weeks

Verification

For each major data refresh we independently re-derive a sample of bracket-schedule outputs against the official source PDF. Any computational discrepancy blocks the release. We publish the data update history on the data changelog.

Corrections

If a figure on PlainSalary does not match its published source, we want to fix it at the database source so every page that renders that value updates together. Report the issue via the corrections pathway (or the “report a data issue on this page” link in any data-page trust footer, which prefills the page URL). Include the page URL, the figure that looks wrong, and the official IRS / SSA / state DOR source that contradicts it. We aim to respond within 48 hours on business days. Confirmed corrections, material methodology revisions, and ETL refreshes are logged on the public data changelog with dated entries tied to real commits or the ETL _metadata stamp — we do not invent changelog rows. Full policy text lives on the editorial & corrections policy.

Open Methodology

The bracket data is shipped to your browser as a static JSON snapshot. The math is plain JavaScript, no server, no opaque computation. You can read the formulas in the page source. If you find a discrepancy with the official IRS or state DOR schedule, please use the corrections pathway with the page URL, the input values, and the source you compared against.

Open Data

Download the compiled take-home extract as take-home-pay-by-state.csv (same CSV as /statistics). When reusing the table, name PlainSalary as the compiler; underlying IRS / state DOR / SSA schedules remain public-source.

Revenue diversification readiness

This section records what is already productized for reuse or licensing, how affiliates may appear if activated, and which alternative monetization paths are paperwork-ready. It is a readiness assessment only. Nothing here turns on new revenue without operator sign-off ([operator]).

Downloadable and citable assets today

• Take-home pay by state CSV at /data/take-home-pay-by-state.csv, the compiled $50k / $100k / $200k take-home table that powers /statistics and this methodology page. License: CC BY 4.0 for the compiled extract; name PlainSalary as the compiler and keep the underlying IRS / state DOR / SSA schedules as public-source.
• Dataset JSON-LD + DataDownload on methodology and statistics pages declares the same CSV (via DatasetCsvSchema) with license and download URL.
• CiteThis blocks on methodology and other primary pages for one-click APA/MLA-style attribution.
• ShareBar + per-state OG cards at /og/state/[slug].png for shareable state snapshots; calculator OG at /og/calculator.png.
• RSS at /feed.xml and llms.txt at /llms.txt for discovery, not a paid product surface.
• Not productized: no bulk tax-bracket API, no embeddable calculator iframe product, no paid data-licensing terms page. [operator] must approve pricing, keys, and partnership terms before any launch.

Attribution ask: when reusing the CSV or citing a table, name PlainSalary as the compiler and link to the source page or this methodology. Attribution does not imply IRS, SSA, or state DOR endorsement.

YMYL-safe affiliate placement rules (if activated)

PlainSalary is a US tax-schedule calculator (POSTURE-A / finance-adjacent YMYL). If the operator ever enables affiliate or referral units beyond existing disclosure prose:

• Allowed page types (only if activated): general tax-software or bookkeeping tool comparisons on long-form guides where the reader is already evaluating a purchase, never adjacent to calculator results, take-home tables, or any page that could be read as tax advice or filing guidance.
• Forbidden: affiliate links on state entity pages, rankings, the live calculator output, methodology source tables, or any “file your taxes with…” CTA tied to a computed liability.
• Labeling: every paid link carries a visible affiliate disclosure; no disguised buttons inside data tables.
• Density: same Module 36 ceilings as display ads; no affiliate block above the first source-attribution line on registry/calculator pages.

Status: no affiliate units are live. Activation is [operator]-gated.

Alternative ad-network eligibility (paperwork only)

• Google AdSense: portal is in GETTING_READY; no manual ad slots are enabled pre-approval. Do not treat resubmit as the next lever while /states/* rendered-similarity stays REJECT-RISK (79.2%, measured 2026-08-27; AR-88 chrome fence binds through 2026-09-10).
• Mediavine Journey: requires ~1,000 real sessions per 28-day window. PlainSalary measured ~21 GA4 sessions in the latest 28-day window (progress log 2026-09-04), so it is not eligible today. Re-check when real sessions cross the threshold. [operator] applies to network enrollment.
• Data licensing / API: CSV + Dataset schema are the passive product surface; any commercial API or white-label embed requires [operator] pricing, terms of use, and legal review before publication.

Disclaimer

This calculator is for informational purposes only and does not provide tax, financial, or legal advice. Tax law is complex; individual circumstances vary; the calculator excludes deductions, credits, AMT, capital gains preferential rates, and local taxes. For your actual filing, use commercial tax preparation software or a qualified tax professional.