Official sources

Federal income tax — tax year 2026

Rate schedules for all filing statuses, standard deductions, the additional standard deduction for age and blindness, and adjusted net capital gain thresholds.

• Rev. Proc. 2025-32, Internal Revenue Bulletin 2025-45 — the primary source for 2026 inflation-adjusted figures.
• Form 1040 and instructions — the return structure our federal calculator follows.

Payroll and self-employment tax

• SSA contribution and benefit base — the Social Security wage base, $184,500 for 2026.
• Publication 15 (Circular E), Employer's Tax Guide — FICA and FUTA mechanics.
• Publication 15-T — the federal income tax withholding methods employers use.
• Schedule SE — self-employment tax.
• Form 940 — annual FUTA return.

FICA and self-employment tax rates, and the Additional Medicare Tax thresholds, are fixed in statute and are not adjusted for inflation, so they carry across tax years unchanged.

Bonus and supplemental wage withholding — tax year 2026

• Publication 15 (Circular E), section 7 — the 22% optional flat rate on supplemental wages and the mandatory 37% on supplemental wages above $1,000,000 in a calendar year. Used by the bonus tax calculator. Last checked 29 July 2026.

State supplemental withholding rates are not published here. Several states set a specific rate for bonuses and others have none; the bonus calculator asks for yours rather than assuming one.

Retirement plan limits — tax year 2026

Elective deferral and catch-up limits, the defined contribution and compensation limits, IRA limits, and the deduction and Roth eligibility phase-out ranges. Applied by the 401(k), employer match, and traditional vs Roth IRA calculators. Last checked 29 July 2026.

• Notice 2025-67 — 2026 amounts relating to retirement plans and IRAs, published in Internal Revenue Bulletin 2025-49. The primary source for every retirement figure on this site.
• IRS newsroom announcement — the same figures in plain language, including the phase-out ranges.

Employer match formulas, vesting schedules, and investment returns are not government figures. They are set by individual plan documents or are assumptions, and every calculator asks for them rather than supplying a default.

Consumer prices

Used by the inflation calculator. Retrieved 29 July 2026.

• Bureau of Labor Statistics, Consumer Price Index — series CUUR0000SA0, CPI-U for the U.S. city average, all items, not seasonally adjusted. Annual averages from 1913 through 2025.

2026 is incomplete. The partial figure carried on this site is the mean of the months published so far and is labelled as partial wherever it appears.

Wage, hour, and lending rules

These publications inform how the paycheck and mortgage calculators describe the rules, rather than supplying dollar figures.

• U.S. Department of Labor — overtime under the Fair Labor Standards Act, including the regular-rate treatment of nondiscretionary bonuses. Informs the overtime pay calculator.
• U.S. Department of Labor — worker misclassification and IRS worker classification guidance. Both are cited by the 1099 vs W-2 calculator, which compares compensation and does not determine classification.
• Consumer Financial Protection Bureau — Loan Estimate. The section structure of the closing costs calculator follows this form so the two can be compared line by line.
• Consumer Financial Protection Bureau — cancelling private mortgage insurance, covering the request right at 80% and automatic termination at 78% under the Homeowners Protection Act. Used by the PMI calculator.

Capital gains and investment income

• Schedule D — capital gains and losses.
• Publication 550 — investment income and expenses.
• Form 8960 — net investment income tax.

Estate and gift tax

• Rev. Proc. 2025-32 — 2026 basic exclusion amount of $15,000,000 and annual gift exclusion of $19,000.
• Form 706 — federal estate tax return.
• Form 709 — gift tax return.

State and local taxes — tax year 2026

Eleven states are published across the state income tax and state paycheck calculators. Each state's figures are transcribed from that state's own revenue department, and every state page lists its specific sources with review dates. The primary publications:

• California EDD — 2026 Withholding Schedules, Method B, and the EDD's 2026 SDI rate.
• New York — 2026 Form IT-2105-I rate schedules, including New York City and Yonkers.
• New Jersey Division of Taxation — rate schedules and exemptions.
• Massachusetts DOR — tax rates, including the 2026 surtax threshold, and its personal exemptions page.
• Illinois DOR — Booklet IL-700-T (2026).
• Pennsylvania DOR — tax rates.
• North Carolina DOR — tax rate schedules and the 2026 NC-30 withholding instructions.
• Georgia DOR — 2026 tax changes and the 2026 Employer's Withholding Tax Guide.
• Federation of Tax Administrators — directory of every state revenue department, used to find the rest.

States not listed on the state pages are unpublished, not approximated: their 2026 schedules had not been confirmed against the state's own publications at the last review. Sales tax rates are supplied by the user for a similar reason — combined rates change frequently and vary by address rather than by city.

Legislation

• IRS guidance on P.L. 119-21 provisions — the deductions for seniors, tips, and overtime, and the changes to the child tax credit and the state and local tax deduction.

Figures deliberately not published

For transparency, these are the specific figures we could not confirm against a primary source and therefore excluded:

• The refundable Additional Child Tax Credit cap for 2026.
• The state and local tax deduction cap for 2026.
• Alternative minimum tax exemption amounts for married filing separately and head of household.
• The increased annual gift exclusion for gifts to a non-citizen spouse.
• 2026 rate schedules, deductions, and exemptions for the states not yet published on the state calculators — published states carry their sources on their own pages.
• All 2025 figures. The site covers tax year 2026 only, because the 2025 rate tables could not be retrieved from a primary source in a form we could verify.
• State supplemental withholding rates for bonuses, state unemployment insurance rates, and workers' compensation rates. All three are set per state or per employer, and the calculators that need them ask for yours.
• PMI rates, mortgage points pricing, and current market interest rates. None is a government figure; each comes from a lender quote you enter.
• Investment returns, house price appreciation, rent growth, and safe withdrawal rates. These are planning assumptions rather than published data, and every page using one says so where the reader is looking.

See the methodology for how these exclusions are handled inside each calculator.