How we calculate
One engine runs every calculator on this site. This page is that engine written out: the constants it uses, the four OBBBA deductions and their differing phase-outs, the rates we could verify and the ones we could not, and a dated log of every change we've made to the tax data.
4 / 4
of the Schedule 1-A deductions are modeled: overtime, tips, vehicle loan interest and 65+.
$184,500
for 2026, announced by SSA in October 2025. We had it wrong until August 3 — the correction is in the log below.
50 + 15
states, plus the cities that levy their own wage tax on top. Only cities with a rate we verified get one.
41 / 50
states publish a flat supplemental rate. The rest are named further down, along with what we do instead.
The model, honestly
Gross pay minus pre-tax contributions gives taxable wages. Federal tax comes off the brackets, FICA off the gross, state and local off their own bases. Nothing is a lookup of somebody else's calculator.
| Filing status | Standard deduction | 10% bracket up to | 37% starts above |
|---|---|---|---|
| Single | $16,100 | $12,400 | $640,600 |
| Married filing jointly | $32,200 | $24,800 | $768,700 |
| Head of household | $24,150 | $17,700 | $640,600 |
All seven brackets from Rev. Proc. 2025-32 are loaded, not just the two shown here.
- 6.2% Social Security, on wages up to $184,500. Above that, nothing.
- 1.45% Medicare, with no cap.
- +0.9% Additional Medicare on wages over $200,000 ($250,000 MFJ).
Employee share only. We don't show the employer's matching half, because it never touches your check.
The state model is a simplification, and we'd rather say so than let you assume otherwise: we apply each state's top marginal rate to income above the federal standard deduction. In a flat-tax state that is exactly right. In a state with genuinely progressive brackets it overstates the tax somewhat, because your first dollars are taxed at lower rates than your last.
Local tax comes from a table of 15 cities with a verified municipal wage rate. There's no field where you type a rate, because a made-up local rate looks exactly like a real one on screen.
The Child Tax Credit is applied at $2,200 per qualifying child, against federal tax owed.
The four OBBBA deductions
Schedule 1-A added four above-the-line deductions for 2025 through 2028. They are usually described together, which hides the thing that matters: each one phases out by a different rule. Getting this wrong is how a calculator quietly overstates a refund.
Overtime premium
the half of time-and-a-half, not the whole overtime check
- Cap
- $12,500 · $25,000 MFJ
- Phase-out from
- $150,000 · $300,000 MFJ
- How it shrinks
- −$100 per complete $1,000 of MAGI over the threshold. A partial thousand rounds down and costs nothing.
Qualified tips
all filing statuses share one cap
- Cap
- $25,000
- Phase-out from
- $150,000 · $300,000 MFJ
- How it shrinks
- −$100 per complete $1,000 over the threshold — the same mechanic as overtime.
Vehicle loan interest
interest only, on a qualifying loan
- Cap
- $10,000
- Phase-out from
- $100,000 · $200,000 MFJ
- How it shrinks
- −$200 per $1,000 over the threshold or any portion of one. This one rounds up: $300 over costs the full $200.
Age 65 and over
$12,000 if both spouses qualify
- Cap
- $6,000 per person
- Phase-out from
- $75,000 · $150,000 MFJ
- How it shrinks
- −6% of the MAGI excess — a smooth taper, no thousand-dollar steps at all.
Take a single filer at $104,300 of MAGI — $4,300 over the vehicle-interest threshold. Because that deduction counts every $1,000 “or portion thereof”, the excess rounds UP to 5 steps and costs $1,000. Run the identical excess through the tips and overtime rule, which only counts complete thousands, and it rounds DOWN to 4 steps and costs $400. Same income, same distance over the line, $600 apart in deduction — and the 65+ deduction uses neither rule, tapering continuously at 6% of the excess.
Sources: IRS Rev. Proc. 2025-32, IRS Schedule 1-A (Form 1040) and its instructions, and IRS Tax Tip 2026-06 with the qualified-overtime FAQ.
Bonuses and supplemental wages
A bonus isn't taxed at a different rate — it's withheld at a different rate, and the difference comes back at filing. The bonus calculator uses the percentage method, which is what most payrolls actually run.
A flat 22% on supplemental wages up to $1,000,000 in a year, and 37% on anything above that — the mandatory rate, not an option the employer picks.
Source: IRS Publication 15 (Circular E), supplemental wages.
7 states publish no flat supplemental rate: CT, DE, HI, MD, NJ, SC, WV. For those we fall back to the regular state estimate and label the result as an estimate on screen. We'd rather show a flagged approximation than a confident wrong number.
The special cases we model by name
California
10.23%applies to bonuses and stock options; other supplemental pay is withheld at 6.6%.
Georgia
5.39%higher than the state's 4.99% regular flat rate — a bonus is withheld harder than a paycheck.
Vermont
30%of the federal amount withheld, not of the bonus — so it moves when the federal rate moves.
Wisconsin
3.54%–7.65%publishes its own tiered supplemental table, picked by annual wages.
New York
11.7%state only; NYC residents add 4.25% local, which this calculator does not apply to bonuses.
Indiana
2.95%before the county add-on of 0.5%–3%, which we don't model.
Massachusetts
5%before the 4% surtax on annual income over $1M, which we don't model.
Every rate was cross-checked against at least two sources — payroll-industry tables and the state's own revenue department — before it went into the engine.
Fiscal changelog
Tax data goes stale, and calculators that never publish a change date are the ones you should worry about. Every change to the constants lands here, corrections included — especially corrections.
- SSA
Social Security wage base corrected from $178,000 to $184,500. The earlier figure was a pre-announcement estimate; the engine now uses the number SSA published in October 2025.
- IRS Schedule 1-A
Added the two remaining OBBBA deductions — vehicle loan interest and the 65+ deduction. The engine now models all four of Schedule 1-A, each with its own phase-out.
- State DORs
Added 2026 state supplemental withholding rates so the bonus calculator uses each state's own rate instead of an annualized estimate.
- MyPayCal
Published the Take-Home Index 2026 — take-home pay computed for all 50 states, released as CSV and JSON under CC BY 4.0.
- IRS Tax Tip 2026-06
Added pre-tax deductions (401(k), HSA, health premiums) and the OBBBA overtime and tips deductions to the engine.
- Rev. Proc. 2025-32
Loaded the 2026 federal brackets, standard deductions and state rates.
Where the model stops
Every calculator has these gaps. Most don't list them. Here's ours, so you know when to trust the number and when to check with a professional.
No year-to-date carryover, no full W-4
Every calculation is standalone and annualized. We don't carry what's already been withheld this year, and we don't model W-4 steps 2 through 4 (second job, claimed dependents, extra withholding). Your actual check can differ on that alone.
No state SUI, SDI or family leave
We don't model employee contributions to state unemployment, disability or paid family leave (CA SDI, NY PFL, WA Cares, NJ FLI and the like). Those are real deductions from your check that don't appear here.
State tax is an approximation
We apply each state's top marginal rate to income above the federal standard deduction. In states with genuinely progressive brackets you'll pay somewhat less than we show, and we include no state deductions or credits.
Only cities with a verified rate
Local tax comes from a lookup table of 15 cities with a municipal wage tax. There is no free-text rate field: we'd rather withhold the number than invent one. Other jurisdictions (Indiana and Maryland counties, Pittsburgh, Grand Rapids) tax wages and aren't in yet.
Pay frequencies
We support annual, monthly, biweekly, weekly and hourly. Semimonthly (twice a month, 24 pay periods) isn't supported yet.
Not tax advice
This is an estimator, not filing software and not personalized advice. For your own situation, talk to an accountant.
Sources and corrections
- IRS Rev. Proc. 2025-32 — 2026 brackets and standard deductions.
- SSA contribution and benefit base — the Social Security wage base.
- IRS Publication 15 (Circular E) — supplemental wage withholding.
- IRS Schedule 1-A (Form 1040) and its instructions, plus IRS Tax Tip 2026-06 — the four OBBBA deductions.
- State revenue departments — state and supplemental rates, cross-checked against payroll-industry tables.
Tell us and we'll fix it and log it — with the date, in the table above, whether the error was ours or the source's. That's the whole point of keeping the log in public.
Last verified: .