2026 Income Tax Calculator Explained

The federal income tax on a year of earnings is a published table applied to a number that is assembled in a few steps. The income tax calculator on this site performs those steps in order and shows the working. The 2026 figures it uses come from Rev. Proc. 2025-32, published in Internal Revenue Bulletin 2025-45 on 3 November 2025.

Nothing on the page is a forecast and nothing is a live figure. The brackets and the standard deduction are the published ones for the 2026 tax year, and every number in the result follows from them and from the values entered.

From gross pay to taxable income

Taxable income is not the number on the pay stub. The calculator starts from gross income for the year, subtracts the pre-tax deductions entered there — a 401(k) contribution, an HSA or an FSA — and then subtracts the deduction.

The deduction is the standard deduction for the filing status, unless an itemized figure larger than it is entered. For 2026 the standard deduction is $16,100 for a single filer and for married filing separately, $32,200 for married filing jointly, and $24,150 for head of household.

What remains is taxable income. The brackets apply to that number, and the state estimate applies to the same number.

How the brackets work

The IRS publishes each bracket as a fixed amount of tax plus a percentage of the excess over the bottom of that bracket, rather than as a flat rate on each slice. For a single filer in 2026, the rates run 10 percent on the first $12,400, 12 percent from there to $50,400, 22 percent to $105,700, 24 percent to $201,775, 32 percent to $256,225, 35 percent to $640,600, and 37 percent on anything above that.

In that form the table reads as a list of checkpoints: the tax is $1,240 at $12,400, $5,800 at $50,400, $17,966 at $105,700, $41,024 at $201,775, $58,448 at $256,225, and $192,979.25 at $640,600. A taxable income of $83,900 for a single filer therefore gives $5,800 plus 22 percent of the $33,500 above $50,400, which is $5,800 plus $7,370 — a federal tax of $13,170.

Two rates come out of that, and they answer different questions. The marginal rate is the rate the next dollar meets, so at $83,900 of taxable income the next dollar is taxed at 22 percent. The effective rate is the whole tax divided by the whole income: the same reader, with gross income of $100,000 and the standard deduction of $16,100, pays $13,170 in federal tax, which is about 13 percent of what they earned.

The standard deduction and itemizing

A dollar of deduction is a dollar of taxable income, and taxable income is taxed at the marginal rate, so a dollar of deduction saves the marginal rate in tax. The size of the deduction therefore matters more to a reader in a higher bracket than to a reader in a lower one: the first dollars of income are taxed at 10 percent, so the standard deduction is worth $16,100 of tax to a single filer at the bottom of the table and considerably more further up.

The calculator asks for the itemized deduction and uses it when it is larger than the standard deduction. Where the itemized figure is smaller, the standard deduction stands and taxable income is higher. The two numbers in the result show which one was used.

What the figure does not cover

The federal figure is ordinary income tax on taxable income, and the calculation stops there. It does not model:

• Tax credits. Credits reduce the tax after it is computed, and no credit is applied here.
• The child tax credit. The same applies to it, and it is one of the largest differences between a tax liability and a tax bill.
• Capital gains rates. The ordinary income rates are applied to the whole of taxable income, with no separate treatment for gains.
• The senior deduction. The additional amount available to older filers is not part of the calculation.

The state tax is a separate calculation and has its own section below.

How the state tax is worked out

The state tax is not a rate applied to the whole of the income. It is calculated the way a state calculates it, from published figures: the brackets, the standard deduction and the personal exemption of the state. Most of them come from the Tax Foundation tables for every state and the District of Columbia. For five states they come from the state itself, because what the state had published for 2026 was newer than the tables: California, Hawaii, Maine, Vermont and Arizona.

The calculation runs in this order.

1. The state starts from the adjusted gross income, which is the gross income less the pre-tax deductions.
2. The state’s own standard deduction comes off, where the state has one, and so does the personal exemption where the state gives it as an exclusion.
3. What is left is taxed with the state’s own brackets, slice by slice: each part of the income is taxed at the rate of the bracket it falls into, which is why a progressive state costs more than a flat one.
4. The credits come off the tax. A state that gives its exemption or its standard deduction as a credit instead of an exclusion gets it here, and so do the state earned income tax credit and the state child tax credit where the model carries them.

The table that is used is the one of the filing status. The states that publish a head of household table of their own have it here, taken from their own forms: New York, New Jersey, Minnesota, Hawaii, Connecticut, Maryland, Maine, Montana, New Mexico, Oregon and California. Idaho treats a head of household return as a joint return, so the joint schedule is the one that applies. Four more states publish no table but give a head of household its own deduction or exemption, and those figures are here as well: Kansas, Oklahoma, Wisconsin and Massachusetts. The rest are calculated with the single filer figures.

Three states let a taxpayer deduct the federal income tax paid from the state taxable income, and where the model does, the deduction comes off the income before the state brackets are applied.

• Alabama takes the whole of it, with no limit on the amount.
• Missouri takes a share of it that depends on the Missouri income: 35% below $25,000, 25% up to $50,000, 15% up to $100,000, 5% up to $125,000 and nothing above that. The result may not exceed $5,000, or $10,000 on a combined return.
• Oregon takes it up to $8,750, and the limit falls away with the income.

The result is a figure that behaves like a state tax: it moves with the income, it moves with the filing status, and it is zero in the nine states that levy no tax on wages at all.

The age of the children

The state child tax credits turn on the age of the child, and the age is asked for band by band rather than as a single number:

Band	Why the band is there
0–3	New York pays $1,000 for a child under four
4–5	the rest of New York’s band
6	Vermont is the one state that pays for a child of six
7–11	Illinois cuts at twelve
12	Massachusetts cuts at thirteen
13–16	the rest of the under-seventeen band
17	Minnesota pays for a child under eighteen

The bands are the ages the states cut at, which is what makes the credits exact rather than approximate. The number of children in them is what the earned income credit counts as well.

The state is a default, not a fact about the reader

The page can fill the state in before the reader touches anything. The network the site is served from knows where a request came from, so the page asks it which state the visitor is in. The state it gets back is approximate: a virtual private network, a corporate proxy or a mobile network can point the answer at the wrong state. The picker is right there, so a reader in the wrong state changes it in one click and every figure moves with it.

A reader who wants the figure from their own return can type the state tax into the field under the state, and that figure replaces the calculated one.

What the state tax does not carry

Four things are left out, and they are worth knowing about.

• Capital gains rates, the surtaxes a few states charge high earners, and the taxes of city and county governments.
• The deduction for state and local income taxes paid, which many states allow inside their itemized deductions.
• Vermont publishes its rates for 2026 as preliminary figures, and it prints the standard deduction and the personal exemption for 2026 with the form, which comes out in 2027, so the amounts the state published last are the ones used here.
• The fall-away of the Maine standard deduction and the Maine personal exemption as the Maine income rises. The deduction starts to shrink at $102,250 for a single filer and is gone at $177,250, and the exemption starts to shrink at $341,000.

The state credits are partial as well. The earned income tax credit is there for the states that set it as a percentage of the federal credit, and for the three that calculate it on their own: California, Minnesota and Wisconsin. Washington has an earned income credit of its own, but it is paid on a separate application and is not part of a tax return, so it is not in the model. The child tax credit is there for the states whose credit turns on the age of the child. The credits of the other states are not in the model, and the ones that are in it do not carry every part of the rule: the figure is the credit the state pays, and a tax return can differ from it.

Payroll taxes are outside this calculation as well. Social Security and Medicare are withheld from wages under their own rates and ceilings, which belong to the net pay calculation rather than to income tax on earnings.

Every figure in the result follows from the published 2026 tables and from the values on the page. Change the income, the filing status, the deduction or the state, and the tax, the effective rate and the income left over all move with them.