Corrections and known limitations

1. Reported. By email, or as an issue on the author's GitHub.
2. Checked against the primary source. The IRS release for federal figures, the state's own department of revenue for state figures. Not a secondary summary, and not another calculator.
3. Fixed in the data, not the page. Every figure comes from one table and one engine, so a correction propagates to every page, chart and image that used it. There is no way to fix a number in one place and leave it wrong in another.
4. Recorded here if it changed a published figure, with the date.

Simplified state deduction models: 0 of 51

No state currently uses a simplified model.

Reciprocity agreements: not yet verified

The state pairs listed on working in another state are long-standing, but each is a separate agreement either state can end. They have not yet been individually confirmed with both revenue departments, and the page says so.

Washington: corrected 5 September 2026

Washington employees pay Paid Family & Medical Leave and WA Cares premiums, 1.24% of wages together, and the table had them. The engine skipped the payroll array for states with no income tax, so no Washington figure included them: take-home was overstated by 1.24% of wages, $744 on a $60,000 salary. Fixed in the engine, with a test that recomputes the Washington figure before every build, and every Washington page, chart and guide rebuilt.

California: corrected 5 September 2026

The California tables held the 2024 schedule, about 3% low at every threshold, and the 2024 standard deduction of $5,540. Checked against the Franchise Tax Board's 2025 rate schedule and corrected to the published 2025 brackets and a $5,706 standard deduction. State tax on a $60,000 salary moved from $1,845 to $1,793. Single and married filers are now verified; the head-of-household schedule is not published on the FTB rate-schedule document and remains the 2024 table, which affects nothing the site displays because every table shows single and married.

Federal figures are 2026; state figures are 2025

This is not an oversight, it is the newest data that exists. The IRS publishes next year's brackets a year ahead, so 2026 federal figures are official. States index their brackets annually and publish the schedule with that year's return, so as of September 2026 the newest California schedule the Franchise Tax Board has released is still 2025, and the same holds across the bracketed states. Every page that shows a state schedule labels it 2025 rather than implying otherwise. When states publish 2026 schedules the tables will be updated and the change logged here.

What is not modelled at all

Federal credits other than the child tax credit and the credit for other dependents, which the calculator does model. That means the earned income credit, education and dependent-care credits and every state-level credit are all absent, as are itemised deductions, capital gains, self-employment tax, supplemental withholding on bonuses, multiple jobs, and mid-year moves between states. The terms of use list these in full.

Federal figures for 2026 — the standard deduction, all seven brackets and the Social Security wage base — were checked against the IRS inflation release and the Social Security Administration. Illinois, Arizona and Utah rates were checked against their own revenue departments. Dates are recorded per figure in the source and shown in each page's byline.

Beyond that, a test suite runs before every deploy. It fails the build if a bracket table does not ascend, if the married standard deduction is not double the single one, if a no-tax state returns anything but zero, if a reciprocity pair is listed in only one direction, or if a state colour would render text below the accessibility contrast floor.

6 September 2026, Vermont brackets and standard deduction. Every Vermont figure was the 2024 schedule. Vermont indexes annually, and the 2025 Schedules X, Y-1 and Z start the 6.6% band at $49,400 single, $82,500 joint and $66,200 head of household, against the $47,900, $79,950 and $64,200 in use. The standard deduction was also a year behind, at $7,400 rather than $7,650 single and $14,850 rather than $15,300 joint. State tax on a $60,000 salary falls from $1,591 to $1,583.

6 September 2026, North Dakota and Nebraska thresholds. Two single-figure transcription errors, both caught by the states' own printed running totals rather than by re-reading the brackets. North Dakota's head-of-household zero band ended at $64,850 rather than $64,950; the state prints $4,026.75 at the next edge, which is only true at $64,950. Nebraska's joint 2.46% band ended at $8,050 rather than $8,040; the state prints $197.78, which is 2.46% of $8,040. Both affect only the filing statuses named.

6 September 2026, Maryland 2025 changes. Maryland's 2025 Budget Reconciliation and Financing Act raised the standard deduction to $3,350 single and $6,700 joint and removed the income phase-in, and added brackets of 6.25% and 6.5% above $500,000. The table still held the previous $2,850 and $5,700, and head-of-household filers were being given the single deduction rather than the joint one. State tax on a $60,000 salary falls from $2,510 to $2,486 for a single filer and from $2,510 to $2,327 for head of household. The local rate cap also rose to 3.30%; Dorchester County took it retroactively for 2025.

5 September 2026, Connecticut personal exemption. Connecticut withdraws the personal exemption as income rises, $1,000 for every $1,000 of income above $30,000 for a single filer, so it is gone entirely by $44,000. The full $15,000 was being applied at every income, which understated Connecticut tax for anyone earning above about $45,000 — on a $60,000 salary by $825, from $1,725 to the $2,550 the state's own tax calculation schedule gives. The withdrawal is now modelled and the engine reproduces that schedule exactly. Connecticut's tax recapture above $200,000 and its personal tax credits at lower incomes are still not modelled, and the state page says so.

5 September 2026, Alabama head of family. The $1,500 single personal exemption was being applied to head-of-family filers. Alabama's Form 40A gives that status $3,000, the same as married filing jointly. Head-of-family state tax on a $60,000 salary falls from $2,625 to $2,550. Single and joint filers were unaffected.

5 September 2026, Wisconsin brackets. The 4.4% band was set to end at $29,370 for single filers and $39,150 for joint filers. The Wisconsin Department of Revenue's 2025 table ends it at $50,480 and $67,300, which its own cumulative figures confirm ($513.80 plus 4.4% of $35,800 is the $2,089 the state prints). Every Wisconsin figure therefore overstated state tax. On a $60,000 salary it falls from $2,045 to $1,895, and take-home rises from $48,345 to $48,495.

5 September 2026, Arkansas brackets. The bracket thresholds were the 2024 indexed figures ($5,500 / $10,900 / $15,600 / $25,700) rather than the 2025 ones ($5,600 / $11,200 / $16,000 / $26,400). Arkansas indexes its brackets every year. Effect on a $60,000 salary: state tax $1,836 to $1,826. The engine now reproduces the state's own published formula to within four cents.

8 September 2026, New Jersey overcharged heads of household by hundreds. New Jersey publishes two rate schedules. Table A is for single filers, and Table B covers married couples filing jointly and heads of household. This site defined only a single and a joint table for New Jersey, so head of household filers fell back to the single schedule, which charges far more at the same income. Effect on a $60,000 salary: state tax $1,767.25 to $1,001.00, take-home $47,845.75 to $48,612.00. At $90,000 the overcharge was $1,456.05. Head of household is the status most single parents file under, so this fell on the people least able to absorb it. Found by reading New Jersey's own rate schedule during a review of the highest-traffic state pages, and all three of its filing statuses are now checked before every build.

8 September 2026, Georgia's note named the wrong rate for next year. The Georgia page said the rate was scheduled to fall to 5.09% in 2026. Georgia legislated a deeper cut than the one originally scheduled, and the Department of Revenue now states that the rate has been reduced to a flat 4.99%. No figure on the site moved, because every Georgia calculation runs on the 2025 rate of 5.19%, but the sentence was published and was wrong. Found while reading the department's own updates during a review of the highest-traffic state pages.

7 September 2026, married couples in Mississippi were charged $440 too much. Mississippi taxes the first $10,000 of taxable income at nothing. Its own Schedule of Tax Computation has a column for the taxpayer and a second column for the spouse, and each gets that first $10,000 free. This site defined only one bracket table for Mississippi, so married couples fell back to the single one and received one zero band instead of two, which overstated their state tax by a flat $440 a year. Effect on a $60,000 married return: state tax $1,469.60 to $1,029.60, take-home $51,100.40 to $51,540.40. Found by reading the department's form during a review of every state whose schedule starts with a 0% band; the arithmetic checks this site already ran could not have caught it, because a table with one column too few is still a valid table.

7 September 2026, twelve states were using next year's standard deduction. Twelve states start from the federal standard deduction rather than publishing their own. The code that supplied it handed them the 2026 federal figure, $16,100, while their brackets are 2025 schedules where $15,750 applied. Too much deduction means too little tax, so all twelve were understated. Arizona, Colorado, DC, Idaho, Iowa, Maine, Missouri, Montana, New Mexico, North Dakota, South Carolina and Utah. Effect on a $60,000 salary, single: between nothing and $23.62 a year depending on the state's rate, with South Carolina moving $1,992.00 to $2,013.00 and North Dakota unchanged because that salary sits below its zero band. The deduction now follows the year of the state schedule, and South Carolina's figure is asserted before every build so the two cannot drift apart again.

7 September 2026, Ohio was wrong twice, and both were understatements. Ohio's published schedule reads “$342.00 plus 2.750% of the amount in excess of $26,050” while the band below it is taxed at 0%, so that $342 is a step at the threshold rather than tax accumulated underneath it. This engine only understood rates on bands, so it never charged the $342 at all, and every Ohio figure here was that much too low for anyone with taxable income above $26,050. Separately, the top band still held 2024's 3.5% rate, which House Bill 96 cut to 3.125% for 2025 and replaces with a flat 2.75% from 2026. Effect on a $65,000 salary: state tax $1,005.13 to $1,347.13, take-home $53,402.38 to $53,060.38. Above $100,000 of taxable income the two corrections pull against each other, and the rate cut gives some of the base back. The engine now carries a base amount, and the department's own worked example from page 18 of the 2025 IT 1040 booklet, $68,050 of taxable income giving $1,497, is asserted before every build.

5 September 2026, South Carolina structure. Not a figure change: the three-band table in use produced tax within 30 cents of the state's published method at every income, but it was a legacy shape. South Carolina's 2025 tables define the tax as 6% less a constant, which is exactly nothing on the first $10,700 and 6% above it. The table now uses that, and reproduces the state's worked example exactly.

5 September 2026, dead source links. The cited source for the 2026 federal figures had 404'd, because the IRS renamed the release when the One Big Beautiful Bill amendments landed, and five state departments had moved their rate pages. All six now resolve, and npm run checklinks checks all 56 cited sources before a deploy.

5 September 2026, Washington payroll premiums. WA PFML and WA Cares (1.24%) were in the table but never applied, because the engine returned early for no-tax states. Effect on a $60,000 salary: premiums $0 to $744, take-home $50,390 to $49,646. Found when the generated state guides showed Washington tying Texas.

5 September 2026 — California income tax. The bracket thresholds and standard deduction were the 2024 figures rather than 2025. Corrected against the FTB 2025 rate schedule. Effect on a $60,000 salary: state tax $1,845 to $1,793, take-home $47,825 to $47,877. Every California page, table and generated chart was rebuilt from the corrected table.