What will I owe in federal income tax?

A return is a subtraction before it is a multiplication. Your wages, box 1 of the W-2, are the starting point: $85,000 at the inputs above, which is also your adjusted gross income when wages are the only income. The standard deduction for single comes off next, $15,750 for 2025, leaving $69,250 of taxable income. That last number is the one the rates touch. Nobody is taxed on their salary.

The rates then apply in slices rather than all at once. The first slice of taxable income is charged at the lowest rate, the next slice at the next rate, and so on, which produces $10,155 of tax here. Credits come off after that, dollar for dollar, and the total tax for the year lands at $10,155. Withholding is the last step and changes nothing about what you owe: $9,000 was already taken out of your checks, so the return settles the difference as a balance due of $1,155.

The calculator shows that whole path as the Form 1040 lines it actually is, numbered the way the form numbers them, so you can hold it next to your own return and find the line that disagrees. That is the point of running a real return engine rather than a bracket formula: the answer is checkable, not just plausible.

Filing status moves the answer more than anything else on the page, because it sets both the standard deduction and where every rate starts. This table holds wages and children fixed and changes only the status.

Read it as one household earning that salary, not two people earning it each. The joint brackets are twice as wide as the single ones, so a single earner filing jointly spreads the same pay across cheaper slices: at $100,000 that is the difference between $13,455 and $7,746. Two earners bringing in that much between them are taxed on the combined figure, and the gap mostly closes. Head of household sits in between, and it is a real filing status only if a qualifying person lives with you.

At the inputs above, the next $100 of wages is taxed at 22.0%. The year as a whole cost 11.9% of income. Both are true, and they answer different questions: the first tells you what a raise, a bonus, or an extra shift is worth after tax, and the second tells you what the year actually cost. The gap exists because the deduction and the lower slices are already spent by the time your last dollar is taxed.

The marginal rate here is measured, not looked up in a table. The calculator computes the return again at $85,100 of wages and divides the difference by 100. That matters for anyone near a credit phase-out: a family losing child tax credit as income rises faces a real rate on the next dollar well above the bracket printed in any chart, and a measured rate catches it while a lookup does not. When the two diverge far enough to matter, the calculator says so in a warning under the answer.

The IRS does not have most filers multiply their exact taxable income by a rate. Below $100,000 of taxable income the Form 1040 instructions send you to the Tax Table, which charges a single amount for every $50 band and computes that amount on the band midpoint. Almost every online calculator ignores this and applies the rate schedule everywhere, which is why they come out a few dollars off the return you file.

This one runs the table. At the inputs above, taxable income of $69,250 sits in the band starting at $69,250, and every dollar in that band is charged the same: $69,251 and $69,299 of taxable income both come to $10,155. One dollar past the band, $69,300 steps up to $10,166, a jump of $11 that is the band width times the bracket, not the extra dollar.

At $100,000 of taxable income the table stops and the rate schedule takes over, computed on the exact dollar. You can watch the switch happen: $99,999 is charged $16,909.00 as a flat table lookup, $100,000 is charged $16,914.00, and one dollar more is charged $16,914.22, which is $0.22 higher. Below the ceiling the answer does not move within a band; above it, every dollar moves it.

A credit is not a deduction. A deduction reduces the income the rates apply to; a credit comes off the tax itself, dollar for dollar, which makes it worth far more. Each qualifying child under 17 with a Social Security number carries a child tax credit, reduced once income climbs high enough. The calculator applies it and reports both the full credit and the part the tax was too small to absorb.

Take a head of household filer earning $45,000 with 2 children under 17. The standard deduction of $23,625 leaves $21,375 of taxable income and $2,225 of tax. The child tax credit is worth $4,400, so $2,225 of it erases the bill to $0 and $2,175 is left with nothing to offset. The earned income credit then adds $2,587 on the payments side, and with $1,200 withheld the return comes to a refund of $3,787.

Here is the gap, stated rather than hidden. Part of that unused $2,175 is refundable as the additional child tax credit on Schedule 8812. This engine computes the credit but does not carry the refundable part to line 28, so the refund shown for a household in this position is a floor. Total tax is unaffected and correct. The calculator raises a warning that names the amount instead of printing a low number quietly, and the children input is capped at 2 because at three the refundable formula changes to one this engine does not compute.

State and local income tax. Nine states charge none, and the rest range from a low flat rate to double digits on high income, which can move your total tax bill more than any federal choice you make. Nothing on this page includes it.

Payroll tax. Social Security and Medicare come out of the same paycheck under their own rules and are not federal income tax; the withholding field here is box 2 of the W-2, not the total of everything withheld. If you are comparing this number to what is missing from your check, payroll tax is most of the difference.

Income that is not wages, and deductions that are not standard. Self-employment and 1099 income, interest, dividends, capital gains, rental income, retirement distributions, and Social Security benefits all change the return in ways this page does not model, and it assumes the standard deduction rather than itemizing. If you itemize, run a full return. Everything here is federal income tax on wage income for 2025 only: the parameter set is the current year, not a history of past brackets, and none of it is tax advice.

This calculator is built to be used without a browser. Every input is a query parameter on this page, and the same parameters on the JSON twin return the complete answer as a document.

GET /tools/income-tax.json?wages=120000&status=married-joint&dependents=2

The response carries inputs after parsing and clamping, result with total tax, the refund or balance due, adjusted gross income, the standard deduction, taxable income, the credits applied and any part the tax was too small to absorb, the effective rate, a measured marginal rate, and form1040, the numbered return lines the answer is built from, plus sensitivity across a wage ladder and across all five filing statuses, drivers ranked by effect with a plain sentence each, assumptions that say for every field whether you supplied it and which source the default came from, sources with URLs and as-of dates, warnings, a disclaimer, and in tool the canonicalUrl and jsonUrl that carry only your non-default parameters. The canonical URL is the answer's permanent address; use it when you cite the number.

Parameters, all optional, in any order:

• wages ($ per year), default $85,000 per year.
• withholding ($ per year), default $9,000 per year.
• dependents (count), default 0.
• status (one of single, married-joint, married-separate, head-of-household, qualifying-surviving-spouse), default single.

Values accept plain numbers and loose human formats such as 100k, $100,000, or 6.5%. Unknown parameters are ignored, values outside a field's range are clamped and reported in warnings, and the endpoint never fails on bad input. Responses are cacheable for a day; the defaults change when their sources publish, and tool.version changes when the method does.

• IRS Rev. Proc. 2024-40 (2025 inflation-adjusted items), as of 2025-01-01. The rate tables, standard deduction, and credit amounts for tax year 2025, as published by the IRS.
• One Big Beautiful Bill Act (P.L. 119-21), as of 2025-07-04. The statute that sets the current standard deduction and the $2,200 child tax credit used for 2025.
• 26 U.S.C. (Internal Revenue Code), as of 2025-01-01. The code sections the calculation implements: § 1 rates, § 63 deduction, § 24 child credit, § 32 earned income credit.

These are the parameter authorities the engine itself reports for every computation, not citations chosen after the fact. The rate tables, standard deduction, and credit amounts come from the IRS revenue procedure and the statute that set them; the code sections are the rules the calculation implements. When the engine loads a different parameter set, this list changes with it.

Carlo is a personal finance agent. It knows your accounts, debts, and goals, so instead of a worked example at the salary you typed it can watch what you actually earn and withhold through the year, and tell you in March what April is going to look like. Text it the question.

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