How we calculate US take-home pay

1. 1
   Read from the official source

   Federal rates and thresholds come from the IRS — Revenue Procedure 2025-32 for the rate schedules and the standard deduction, Publication 15 for Social Security and Medicare, Publication 15-T for the withholding tables and the Form 8959 instructions for the Additional Medicare Tax. State figures come from that state's own revenue department and its own statutes. We never copy commercial rate tables. Each number is stored with its source link and the date we read it.

2. 2
   Checked again from a second source

   A separate check re-reads every number from a different official document — the Publication 15 rate against the Social Security Administration's own announcement, a state's withholding guide against its code. Any mismatch stops the update, and a state whose figures have been read only once is refused by name instead of estimated.

3. 3
   Tested against known answers

   The calculators must reproduce 196 hand-derived cases to the cent: 87 on a year's liability from the rate schedules and the standard deduction, and 109 on a single paycheck from the Publication 15-T worksheet. Each one carries the IRS document it was derived from and the arithmetic, and all of them are published below.

4. 4
   Cross-checked by a second calculator

   An independent reference calculator, written separately and sharing no code with the one this site runs, works out 3,782 generated cases. The two must agree exactly, to the cent, before a release.

5. 5
   Published with a version number

   Each release has a rules version, v2026.6 today, shown under every result and recorded in the changelog. Old versions never change: a correction is a new version, never an edit to a published one.

Six of the hand-derived cases carry a refusal instead of an expected figure: the input names something the rules cannot price, and both calculators must refuse it with the same reason rather than answer. The hand derivation of the part of the law that is sourced is published beside each one, so you can see what is known, what is not, and which of the two was acted on.

• 3 cases: Form A-4 prints the elections as 0.5, 1.0, 1.5, 2.0, 2.5, 3.0 and 3.5 per cent and says 'check only one percentage', so a number that is not one of the seven is not an Arizona election at all.
• 2 cases: OBBBA §70103 adds a further deduction per individual aged 65 or over for 2025-2028, on top of the §63(f) amount derived here, and the rules file carries no figure for it.
• 1 case: The zero election is real and printed — Form A-4 (2026) box 2 reads 'I elect an Arizona withholding percentage of zero' — and the rules file's electionPercentages carries seven values from 0.5% to 3.5% and not zero, so the engine refuses it.

The twenty-five we answer: Arkansas, California, Connecticut, Delaware, Florida, Georgia, Hawaii, Illinois, Indiana, Kansas, Kentucky, Louisiana, Mississippi, Missouri, Nebraska, Nevada, New Hampshire, Oklahoma, Rhode Island, South Dakota, Tennessee, Texas, Virginia, Wisconsin and Wyoming. Florida, Nevada, New Hampshire, South Dakota, Tennessee, Texas and Wyoming levy no tax on wage income, read from two of their own official documents, so there federal tax and FICA are the whole deduction. Arkansas, California, Connecticut, Delaware, Georgia, Hawaii, Illinois, Indiana, Kansas, Kentucky, Louisiana, Mississippi, Missouri, Nebraska, Oklahoma, Rhode Island, Virginia and Wisconsin do tax wage income, and the figure shown for them is what an employer withholds under their own published method.

The federal figures on this site are a year's liability on the basis your return settles. A state figure is a different quantity: it is that state's own published withholding computation run over a full year of the pay you gave us, which is what an employer deducts. For most pay the two land close together, and they are not the same thing — California's schedules carry a statutory markup its own law requires, and Virginia is computed as though no exemption certificate had been filed. What your return finally charges can differ, and the answer beside every state figure says so.

The Month and Biweekly columns show what one paycheck has withheld, worked the way the state works a paycheck: Arkansas, California, Connecticut, Delaware, Georgia, Hawaii, Illinois, Indiana, Kansas, Kentucky, Louisiana, Mississippi, Missouri, Nebraska, Oklahoma, Rhode Island, Virginia and Wisconsin start from the pay itself, to the cent. The Year column is the year's figure. The two can differ by more than rounding in one place: California's low-income exemption, which the state tests one paycheck at a time against its limit for that pay period. Those limits are not the yearly limit divided, so on a salary within a few dollars of one, each paycheck can be taxed while the year is exempt, or each paycheck exempt while the year is taxed.

Federal income tax withheld from one paycheck is different again: your employer withholds from the Form W-4 you filed, using the Publication 15-T tables, and what comes out over a year is rarely what the return charges. Both bases are tested here, 109 published cases for the paycheck and 87 for the year, and they are never mixed in one figure. Every federal rate, threshold and wage base behind both is listed on thefederal tax rates page, and the paycheck calculatorcomputes from those same figures.

• Twenty-five of fifty-one jurisdictions, and not all of one kind. Arkansas, California, Connecticut, Delaware, Georgia, Hawaii, Illinois, Indiana, Kansas, Kentucky, Louisiana, Mississippi, Missouri, Nebraska, Oklahoma, Rhode Island, Virginia and Wisconsin tax wage income, and the figure shown for them is what an employer withholds under their own published method. Florida, Nevada, New Hampshire, South Dakota, Tennessee, Texas and Wyoming levy no tax on wage income at all, so the nil shown for them is their own law read from two official documents and not a figure this site is missing. The other 25 states and the District of Columbia are refused BY NAME on every page and never estimated — this site shows no figure for them rather than a plausible one.
• Every state figure is withholding, not the tax you finally owe. California carries the statutory 1.1 markup that Revenue and Taxation Code section 18663(a)(2) requires of its withholding schedules, so its figure runs about ten percent above the tax its own tables imply and the difference comes back when you file. Virginia is computed with ZERO personal exemptions, because the figure assumes no Form VA-4 has been filed and the exemption is counted from that form — someone who has filed one claiming a single exemption is withheld less than this page shows (at $185,000, $9,823.40 against the $9,876.88 shown). Virginia withholding does not vary by filing status at all: Form VA-4 carries exemptions, not status.
• An oracle checks some state figures and no per-paycheck figure. PolicyEngine-US exposes state_withheld_income_tax, which is the same quantity this site reports, so a state that levies nothing on wage income reconciles against it exactly, and a state whose published withholding method PolicyEngine implements is compared to the cent — with one exception recorded in the ledger, an amount whose exact value is half a cent, where this engine rounds away from zero and the oracle toward it. Where PolicyEngine returns a state's annual LIABILITY after credits rather than its withholding, the two are not the same quantity and cannot be compared; those states' figures are arbitrated against the published method instead, and the ledger records the gap and its cause. The Publication 15-T per-paycheck figures have no oracle at all — not one variable for the percentage method or the wage-bracket method. So all 3,975 state cases and all 3,700 paycheck cases are checked in addition by this engine against the independent reference calculator in reference/, which reads the same rules and shares no code with it.
• California refuses a qualifying surviving spouse by name. No 2026 Franchise Tax Board liability parameters are published, and Revenue and Taxation Code section 17041, which would settle which schedule such a filer reads, could not be retrieved (leginfo.legislature.ca.gov answers 403). The engine refuses rather than guessing.
• One earner, one wage, the standard deduction. No tax credits of any kind, the Child Tax Credit and the Earned Income Tax Credit included; no dependents; no itemized deductions; no self-employment, investment or other non-wage income; no second earner.
• Age 65 and over is refused by name. The deduction at section 70103 of Public Law 119-21 is not carried, and the spouse age and blindness boxes are not modeled.
• No local income tax. New York City, Philadelphia and every other local wage tax is unmodeled. Where a state this site answers has one, such as Indiana's county income tax, the figure leaves it out and says so in a notice directly under it; a state this site does not answer is refused by name, and the list of refused states on this page gives each one its own reason.

The rules file sets its own update window: 30 days from a published change, such as a new revenue procedure, a new edition of Publication 15 or a state's schedules for a new year. A confirmed mistake is corrected as a new rules version with a changelog entry, never as an edit to a published one — a version that has produced a figure for a reader never changes. The version and the date these figures were last checked are under every result, and the changelogrecords each change.