Methodology and data status

Every calculator on this site runs the same open sequence of rules against a dated set of parameters. This page lists both.

Calculation sequence

Net profit = self-employment income − business expenses (Schedule C). Losses are treated as zero profit.
Self-employment tax (Schedule SE): net profit × 0.9235 = net earnings. Social Security at 12.4% on net earnings up to the wage base, less any W-2 wages already subject to Social Security; Medicare at 2.9000000000000004% on all net earnings; Additional Medicare Tax at 0.8999999999999999% on wages plus net earnings above the filing-status threshold. Nothing is owed below $400 of net earnings.
Adjusted gross income = net profit + W-2 wages − half of self-employment tax (Schedule 1).
Qualified business income deduction (§199A): 20% of the lesser of qualified business income (net profit minus the deductible half of SE tax) and taxable income before the deduction. Above the taxable-income threshold it phases out linearly over the phase-in range, on the assumption of a sole proprietor with no W-2 employees and no qualified property.
Taxable income = AGI − standard deduction − QBI deduction. Itemized deductions are not modeled.
Federal income tax from the bracket schedule for the filing status.
Child tax credit (§24): per-child and per-other-dependent amounts, reduced by $50 per $1,000 (or part) of AGI over the threshold; the nonrefundable part offsets income tax, and the refundable part (Schedule 8812) is limited per child and by 15% of earned income over $2,500.
Earned income credit (§32): for filers with qualifying children, the credit rate times earned income up to the maximum for that number of children, reduced at the phase-out rate on the greater of AGI or earned income above the threshold (joint filers use the higher threshold); fully refundable. Computed by formula rather than the IRS lookup table, so it can differ from the table by a few dollars. Married-filing-separately filers and filers with investment income above the limit get none; the small credit for filers without children is not computed because it depends on age (25–64), which the calculator does not ask.
State income tax by state model, described below.
Quarterly estimate = (federal + state total) ÷ 4. Safe-harbor alternatives (100% / 110% of prior-year tax) are described on each page but not calculated.

State models

No income tax (Alaska, Florida, New Hampshire, Nevada, South Dakota, Tennessee, Texas, Washington, Wyoming): state tax is zero. State-level business taxes that may still apply are described on each page but not calculated.

Bracket states: a single model driven by one data file per state and year. The file declares the bracket schedule, standard deduction, personal and dependent exemptions (as deductions or credits, flat or stepped by income), whether the state conforms to federal AGI (and therefore allows the half-SE-tax deduction), and any business-income deduction with a separate flat rate on the excess. Local income taxes are never calculated.

California: its own module, because of the Mental Health Services Tax and exemption credits.

Not modeled

Itemized deductions; self-employed health insurance deduction; SEP-IRA, Solo 401(k) and other retirement contributions.
S-corporation or partnership elections; multiple businesses; net operating losses.
Credits other than the child tax credit and the earned income credit: education credits, the child and dependent care credit, premium tax credit, and all state credits. The childless earned income credit is left out because it depends on age.
City, county and school-district income taxes.
Phase-outs of state exemptions at high income where noted in a state's data file.

Each of these usually lowers the tax owed, so the estimate is generally conservative — but not always; check the notes on your state's page.

Data files and verification status

Every parameter set carries a status. draft means the figures were entered from the cited publication but have not yet been re-checked line by line against it; verified means that on the date shown, two independent reads of the primary documents (the revenue procedure, form instructions, or statute — never a third-party summary) produced the same figures, and every difference from the draft was corrected and logged in the file's notes. The verifier is not a licensed tax professional; the check is documentary, and the documents are cited so you can repeat it. Pages for states whose data is still draft are marked as such and kept out of search indexes.

Data set	Status	Last verified	Sources
US federal 2025	verified	2026-09-05	IRS Rev. Proc. 2024-40 (original 2025 inflation adjustments) Public Law 119-21 (One Big Beautiful Bill Act) — raised 2025 standard deduction, made QBI permanent, set CTC to $2,200 SSA 2025 COLA fact sheet — Social Security wage base IRS Form 1040-ES (2025) — estimated tax due dates IRS Rev. Proc. 2024-40 §2.06 — earned income credit amounts and §32(i) investment income limit Verification: Two independent primary-source checks on 2026-09-05 (Rev. Proc. 2024-40 §3.01/§2.05/§2.27, Rev. Proc. 2025-32 §3–4, Form 1040-ES 2025/2026 rate schedules and SE worksheet, Form 8959 and Schedule 8812 instructions, P.L. 119-21 §§70102/70104/70105, SSA contribution and benefit base table); the two checks agreed on every figure. Notes EITC parameters (2025): earned income amount, maximum credit and phase-out points read from the revenue procedure table; credit and phase-out rates are statutory (§32(b)(1)). The credit is computed by formula, not by the Form 1040 lookup table, so results can differ from the table by up to about $8. The childless credit is only computed when the caller asserts the 25–64 age rule is met. 2026-09-05 audit: HoH 32% bracket ceiling corrected from 250,525 (single figure) to 250,500 per Rev. Proc. 2024-40 Table 2. HoH upper brackets are indexed separately from single and must never be copied from it. Standard deduction reflects the OBBBA-amended 2025 amounts, not the original Rev. Proc. 2024-40 figures. Additional Medicare tax thresholds and CTC phase-out thresholds are statutory and not inflation-indexed.
US federal 2026	verified	2026-09-05	IRS Rev. Proc. 2025-32 (2026 inflation adjustments, incorporating OBBBA changes) SSA 2026 COLA fact sheet — Social Security wage base 26 U.S.C. §199A as amended by Public Law 119-21 — QBI phase-in range widened to $75,000 / $150,000 26 U.S.C. §24 as amended by Public Law 119-21 — CTC $2,200, indexed from 2026 IRS Form 1040-ES (2026) — estimated tax due dates IRS Rev. Proc. 2025-32 §4.06 — earned income credit amounts and §32(i) investment income limit Verification: Two independent primary-source checks on 2026-09-05 (Rev. Proc. 2024-40 §3.01/§2.05/§2.27, Rev. Proc. 2025-32 §3–4, Form 1040-ES 2025/2026 rate schedules and SE worksheet, Form 8959 and Schedule 8812 instructions, P.L. 119-21 §§70102/70104/70105, SSA contribution and benefit base table); the two checks agreed on every figure. Notes EITC parameters (2026): earned income amount, maximum credit and phase-out points read from the revenue procedure table; credit and phase-out rates are statutory (§32(b)(1)). The credit is computed by formula, not by the Form 1040 lookup table, so results can differ from the table by up to about $8. The childless credit is only computed when the caller asserts the 25–64 age rule is met. 2026-09-05 audit: HoH 24%/32% ceilings corrected to 201,750/256,200 (Rev. Proc. 2025-32 Table 2); QBI MFS threshold corrected to 201,775 (§4.26 lists MFS separately from all other returns); ACTC limit corrected from 1,800 to 1,700 (§4.05(2) — the indexed $1,400 base did not reach the next $100 step). CTC $2,200 and ACTC $1,700 are inflation-indexed from 2026 with round-down to $100; both stayed flat for 2026 (Rev. Proc. 2025-32 §4.05). §199A(i) (added by P.L. 119-21 §70105) guarantees a $400 deduction from 2026 for taxpayers with at least $1,000 of QBI from a business in which they materially participate; the calculator assumes material participation. Additional Medicare tax thresholds and CTC phase-out thresholds are statutory and not inflation-indexed.
California 2025	verified	2026-09-05	California FTB 2025 Form 540 Tax Rate Schedules (Schedules X, Y, Z) — https://www.ftb.ca.gov/forms/2025/2025-540-tax-rate-schedules.pdf FTB Tax News, October 2025 — 2025 indexing: standard deduction, exemption credits (CCPI factor 3.0%) 2025 Form 540 Booklet, line 62 — Behavioral Health Services Tax (1% over $1,000,000 taxable income) 2025 Schedule CA (540) instructions, Part I Section C line 15 — no adjustment to the federal ½-SE-tax deduction Verification: Two independent primary-source reads on 2026-09-05 (state 2025 form instructions / rate schedules, statute or enacted 2025 legislation), reconciled; every difference from the draft corrected and logged in notes. Notes 2026-09-05 audit: all 24 bracket thresholds replaced. The draft had scaled the prior-year schedule by the wrong inflation factor (~2.3% instead of the FTB's 3.0%); single/MFS, joint and head-of-household schedules now match FTB Schedules X, Y and Z exactly. Standard deduction and exemption credits were already correct. Exemption credits phase out at high income ($6 per exemption for each $2,500 of federal AGI over $252,203 single/MFS, $504,411 joint, $378,310 HoH) — not modeled; overstates credits by at most $153 + $475 per dependent for those filers. The 1% tax on taxable income over $1,000,000 was renamed Behavioral Health Services Tax for 2025; the JSON key keeps the former name. California does not allow the federal §199A deduction; because it is below-the-line federally it never enters CA AGI, so no adjustment is needed. 2026 California figures are published by the FTB in late 2026; until then sites fall back to this file and say so.
Arizona 2025	verified	2026-09-05	Arizona Department of Revenue — 2025 Form 140 instructions A.R.S. §43-1011 (2.5% flat rate), §43-1041 (standard deduction conforms to federal), §43-1073.01 (dependent tax credit) Verification: Two independent primary-source reads on 2026-09-05 (state 2025 form instructions / rate schedules, statute or enacted 2025 legislation), reconciled; every difference from the draft corrected and logged in notes. Notes 2026-09-05 audit: 2.5% rate, standard deduction and dependent credit confirmed against the 2025 Form 140 instructions and A.R.S. §43-1073.01. The 2025 standard deduction equals the OBBBA-amended federal amounts by virtue of H.B. 4168 (Laws 2026, signed 2026-06-13), which set $15,750/$23,625/$31,500 retroactively for 2025. Added the credit phase-out: 5% for each $1,000 or fraction of federal AGI over $200,000 ($400,000 joint), gone once the excess exceeds $19,000. For 2026 the under-17 dependent credit rises to $125 (H.B. 4168); a 2026 file is needed. Not modeled: the standard-deduction increase equal to 34% of charitable contributions, and the 2025 tips/overtime subtractions.
Georgia 2025	verified	2026-09-05	Georgia Department of Revenue — 2025 Form 500 instructions O.C.G.A. §48-7-20 as amended by H.B. 111 (2025) — 5.19% rate for 2025 O.C.G.A. §48-7-27 — standard deduction and dependent exemption Verification: Two independent primary-source reads on 2026-09-05 (state 2025 form instructions / rate schedules, statute or enacted 2025 legislation), reconciled; every difference from the draft corrected and logged in notes. Notes 2026-09-05 audit: 5.19% rate (H.B. 111 §1), $12,000/$24,000 standard deduction and $4,000 dependent exemption confirmed against the 2025 IT-511 booklet (Form 500 lines 11, 14, 16). No personal exemption for the filer exists. No figures changed. The Department of Revenue lists 4.99% and a $15,000/$30,000 standard deduction for 2026; whether the H.B. 111 revenue triggers were met was not independently confirmed — a 2026 file must cite the DOR notice. Not modeled: low income credit (federal AGI under $20,000), child and dependent care credit.
Illinois 2025	verified	2026-09-05	Illinois Department of Revenue — 2025 Form IL-1040 instructions (rate 4.95%, line 1 = federal AGI) 2025 IL-1040 Line 10a Exemption Allowance Chart — $2,850 per person; no allowance when federal AGI exceeds $250,000 ($500,000 joint) Informational Bulletin FY 2026-15 (2026 exemption $2,925) 35 ILCS 5/201 (rate), 35 ILCS 5/204 (exemption) Verification: Two independent primary-source reads on 2026-09-05 (state 2025 form instructions / rate schedules, statute or enacted 2025 legislation), reconciled; every difference from the draft corrected and logged in notes. Notes 2026-09-05 audit: rate and $2,850 exemption confirmed. Added the exemption cliff: the entire exemption allowance (filer and dependents) is $0 when federal AGI exceeds $250,000 (single/HoH/MFS) or $500,000 (joint). It is a cliff, not a phase-out. Not modeled: the extra $1,000 exemption for filers 65+ or blind; Illinois EITC (20% of federal) and the Illinois child tax credit (40% of the state EITC). 2026 exemption is $2,925 per Bulletin FY 2026-15; a 2026 file is needed.
Michigan 2025	verified	2026-09-05	Michigan Department of Treasury — 2025 MI-1040 Instruction Book (rate p.3 and line 17; exemption $5,800 line 9a; Schedule 1 line 2 add-back of the federal self-employment tax deduction, p.11) MCL 206.51 (4.25% rate), MCL 206.30(1)(b) (add back taxes on or measured by income deducted in arriving at AGI), MCL 206.30 (exemption, indexed) Verification: Two independent primary-source reads on 2026-09-05 (state 2025 form instructions / rate schedules, statute or enacted 2025 legislation), reconciled; every difference from the draft corrected and logged in notes. Notes 2026-09-05 audit: rate and $5,800 exemption confirmed. Corrected: Michigan requires the federal deduction for half of self-employment tax to be added back (Schedule 1, line 2), so allowsHalfSeDeduction is false. Other federal adjustments such as self-employed health insurance are not added back; when those inputs are added to the engine, Michigan must apply them. Not modeled: Michigan EITC (30% of federal), homestead property tax credit, and the age-based standard deductions for taxpayers born before 1953.
North Carolina 2025	verified	2026-09-05	North Carolina Department of Revenue — 2025 Form D-401 instructions (rate p.5, standard deduction line 11, child deduction table p.13, line 6 = federal AGI) N.C.G.S. §105-153.7 (4.25% for 2025, 3.99% for taxable years after 2025), §105-153.5(a)(1) (standard deduction), §105-153.5(a1) (child deduction) Verification: Two independent primary-source reads on 2026-09-05 (state 2025 form instructions / rate schedules, statute or enacted 2025 legislation), reconciled; every difference from the draft corrected and logged in notes. Notes 2026-09-05 audit: rate, standard deductions and child-deduction amounts confirmed; every AGI tier boundary in the draft was exactly double the statutory figure and has been corrected (steps of $10,000 single/MFS, $15,000 HoH, $20,000 joint). The deduction applies only to children who qualify for the federal child tax credit; other dependents get nothing. The rate falls to 3.99% for 2026; a 2026 file is needed before the fallback is acceptable. North Carolina has no state EITC or child credit; nothing further is missing for a typical sole proprietor.
New Jersey 2025	verified	2026-09-05	New Jersey Division of Taxation — 2025 Form NJ-1040 instructions, tax rate schedules N.J.S.A. 54A:2-1 (rates), 54A:3-1 (personal and dependent exemptions) Verification: Two independent primary-source reads on 2026-09-05 (state 2025 form instructions / rate schedules, statute or enacted 2025 legislation), reconciled; every difference from the draft corrected and logged in notes. Notes 2026-09-05 audit: brackets, exemptions and the no-half-SE rule confirmed against the 2025 NJ-1040 instructions (Schedule NJ-BUS-1 Part I allows no adjustment for self-employment tax). Added the filing threshold: no tax when gross income is $10,000 or less ($20,000 joint or head of household) — a cliff measured on gross income before exemptions. New Jersey does allow the self-employed health insurance deduction and self-employed 401(k) contributions; when those inputs exist in the engine, New Jersey must apply them (SEP and IRA contributions are not deductible). Not modeled: NJ EITC (40% of federal), NJ child tax credit for children 5 and under with taxable income up to $80,000, property tax deduction/credit, and the health-coverage shared responsibility payment.
New York 2025	verified	2026-09-05	New York State Department of Taxation and Finance — 2025 Form IT-201 instructions: tax rate schedule, standard deduction (line 34), dependent exemption (line 36), and tax computation worksheets 1–16 for New York AGI over $107,650 N.Y. Tax Law §601 (rates and tax benefit recapture, as amended by Ch. 59 of the Laws of 2025 Part A), §614 (standard deduction), §616 (dependent exemption) Verification: Two independent primary-source reads on 2026-09-05 (2025 IT-201 instructions and Tax Law §601), reconciled; the tax benefit recapture worksheets were transcribed from the same instructions on 2026-09-06 and every published recapture base and incremental benefit amount is re-derived from the rate schedule in the test suite. Notes 2026-09-05 audit: brackets, standard deduction and $1,000 dependent exemption confirmed; 2025 rates are unchanged by the FY2026 budget (the 0.1-point cuts to the five lowest rates start in tax year 2026, with a further 0.1 in 2027). 2026-09-06: tax benefit recapture implemented from the IT-201 tax computation worksheets. Above $107,650 of New York AGI the benefit of the lower brackets is phased out over $50,000 of AGI, first to the rate of the bracket containing the first recapture threshold (5.5% joint, 6% others), then tier by tier with the published recapture base and incremental benefit amounts; above $25,000,000 all taxable income is taxed at 10.9%. Worksheet factors are rounded to four decimals as instructed. Not modeled: the MCTMT on net self-employment earnings over $50,000 allocated to the Metropolitan Commuter Transportation District (0.60% in New York City counties, 0.34% in Dutchess, Nassau, Orange, Putnam, Rockland, Suffolk and Westchester), New York City and Yonkers resident income taxes, the refundable New York EITC (30% of federal), the Empire State child credit, and the household credit. The page states these plainly. The $8,000 single standard deduction applies to filers who cannot be claimed as a dependent ($3,100 otherwise). A 2026 file is needed (rates 3.9/4.4/5.15/5.4/5.9% on the five lowest brackets; recapture amounts change with them).
Ohio 2025	verified	2026-09-06	Ohio Department of Taxation — 2025 Ohio IT 1040 booklet (rate schedule p.4/18, exemption table p.17, business income deduction p.11/27) and 2025 IT BUS schedule Ohio Rev. Code §5747.02 (rates, as amended by H.B. 96 of 2025), §5747.01(A)(28) (business income deduction), §5747.025 (personal exemption) Verification: Two independent primary-source reads on 2026-09-05 (2025 Ohio IT 1040 booklet, IT BUS schedule, R.C. 5747.01/5747.02/5747.025), reconciled; the nonbusiness schedule was re-read on 2026-09-06 against both the booklet (p.18) and the statute text at codes.ohio.gov, and the booklet's worked example is reproduced in the test suite. Notes 2026-09-05 audit: brackets, exemption tiers, business income deduction amounts and the flat 3% rate all match the 2025 booklet and statute. A fourth exemption tier (MAGI $750,000 and above → $0) was added, and the business income mechanics follow the IT BUS schedule: the deduction is the lesser of business income, federal AGI and $250,000; business income taxed at 3% is capped at Ohio taxable income after exemptions; only what remains goes through the brackets. Exemption tiers key off MAGI (Ohio AGI before the deduction), which for a sole proprietor equals federal AGI. 2026-09-06: the nonbusiness schedule's apparent inconsistency is in the statute itself. R.C. 5747.02(A)(3)(b) for 2025 reads '$342.00 plus 2.75% of the amount in excess of $26,050' up to $100,000 and '$2,394.32 plus 3.125% of the amount in excess of $100,000' above it; $342 + 2.75% × $73,950 = $2,375.63, so the schedule steps up by $18.695 at $100,000 (the $2,394.32 base is the unchanged 2024 figure). The booklet (p.18) prints the same lines, and its worked example ($68,050 → $1,497) confirms the $342 step. The engine reproduces the statute as written: a $342 step above $26,050 and an $18.695 step above $100,000. Only filers with nonbusiness income above $100,000 are affected. H.B. 96 sets a single 2.75% rate with a $332 step at $26,050 for 2026 and later (R.C. 5747.02(A)(3)(c)) and no second step; a 2026 file is needed once the 2026 exemption amounts are published. The $20 per-exemption credit for MAGI under $30,000, the joint filing credit, and school district income taxes are not modeled.
Pennsylvania 2025	verified	2026-09-05	Pennsylvania Department of Revenue — 2025 PA-40 instructions 72 P.S. §7302 — 3.07% flat rate Verification: Two independent primary-source reads on 2026-09-05 (state 2025 form instructions / rate schedules, statute or enacted 2025 legislation), reconciled; every difference from the draft corrected and logged in notes. Notes 2026-09-05 audit: 3.07% rate, absence of a standard deduction and exemptions, and the disallowance of the federal ½-SE-tax deduction confirmed against the 2025 PA-40 instructions and the PA Personal Income Tax Guide (net profits class; 'one-half of self-employment taxes — no provision'). No figures changed. Not modeled: Tax Forgiveness (Schedule SP), which can eliminate tax for low-income filers (100% forgiveness at eligibility income up to $6,500 single, plus $9,500 per dependent, phasing out over the next $2,250). Pennsylvania also disallows SEP/IRA and other federal above-the-line deductions. Local earned income / net profits taxes (typically 1%; Philadelphia 3.75%) are outside this model.
Virginia 2025	verified	2026-09-05	Virginia Department of Taxation — 2025 Form 760 instructions Va. Code §58.1-320 (rates), §58.1-322.03 (standard deduction as amended by the 2025 budget), §58.1-322.03 (personal exemption $930) Verification: Two independent primary-source reads on 2026-09-05 (state 2025 form instructions / rate schedules, statute or enacted 2025 legislation), reconciled; every difference from the draft corrected and logged in notes. Notes 2026-09-05 audit: brackets, $8,750/$17,500 standard deduction (2025 Form 760 instructions, line 11; Va. Code §58.1-322.03 as amended for 2025–2026) and the $930 exemption confirmed. Head of household is not a separate Virginia filing status; it uses the single amount. Added the filing threshold: no tax when Virginia AGI is below $11,950 ($23,900 joint). The $8,750/$17,500 amounts apply to 2025 and 2026; 2026 legislation sets $9,200/$18,400 for 2027 and $9,300/$18,600 for 2028–2029. Not modeled: credit for low-income individuals or Virginia EITC (20% of federal, one or the other), spouse tax adjustment for joint filers, age deduction for 65+.

Update cadence

Federal figures are refreshed when the IRS publishes the annual inflation adjustments (usually October or November) and the SSA announces the Social Security wage base. State figures are refreshed when each state publishes its form instructions for the year, typically between October and January. Mid-year legislative changes are applied when enacted and noted in the affected file.

Testing

The calculation engine has an automated test for every rule above, using hand-worked examples, and the site cannot be built if a test fails. Official worked examples from form instructions are added as tests as each data set is verified.

Differential testing

On 2026-09-06 six sets of inputs were entered into two independent calculators and compared line by line with this engine. Against TurboTax TaxCaster (tax year 2025, federal only) taxable income and total federal tax agreed within $1 on all six — including a joint return with W-2 wages and two children (child tax credit $4,400 on both), a head-of-household filer with a refundable credit, and a $200,000 profit that crosses the Social Security wage base. The one difference at the time was the earned income credit, which TaxCaster included and this calculator did not; the credit has since been added and the same case now matches TaxCaster's $4,319 of credits within $1. Against Keeper's 1099 calculator, which at the time computed with tax year 2026 parameters, taxable income, income tax and self-employment tax agreed within $1 on all comparable cases when this engine was run for 2026; Keeper's state figures for California and North Carolina did not match those states' published 2025 schedules and were not used as a reference.

The confirmed figures are pinned as tests, so a future change that moves any of them fails the build. The scripts that drive both calculators are kept in the repository so the comparison can be repeated after each annual data update.

Corrections

Maintained by Meldrov, independent developer and publisher. To report a discrepancy, email support@clearselftax.com with the page, the inputs you used, the figure you expected and the official source for it. Confirmed corrections are applied to the data file, noted in its history, and reflected here.