Income Tax Calculator

What this calculator does

See about how much federal income tax you'll owe for 2026, and whether a refund is likely. US income tax works in slices. Your income is split into bands, and each band is taxed at its own rate, from 10% up to 37%. The calculator uses the 2026 brackets and standard deduction for your filing status. It shows your estimated tax and which bracket your last dollar falls in. It also shows your effective rate, the share of your whole income that goes to tax, and how much tax each bracket adds.

Add the tax already taken out of your paychecks, and it also estimates your refund or what you still owe. Everything here is federal and for tax year 2026. State tax is included only as one optional flat rate. Use the result as an estimate for planning, not as tax advice.

Where it's used

Why this math matters outside the classroom:

• Marginal brackets. Income that crosses into a higher bracket is taxed at that rate only on the dollars above the threshold, not on the whole income.
• Effective rate. Dividing total tax by income gives an average rate that is lower than the top bracket rate under a progressive system.
• Standard deduction. Taxpayers subtract the deduction from income first and then apply the bracket rates to what remains.
• Civics and economics classes. Students apply each bracket rate to its slice of income and add the pieces to see how progressive tax works.

Grade level and standards: Grades 7–8; Common Core State Standards for Mathematics 7.RP.A.3. © Copyright 2010. National Governors Association Center for Best Practices and Council of Chief State School Officers. All rights reserved.

How to use it

1. Choose your 2026 filing status and enter your gross income, your total income for the year before taxes.
2. Enter any pre-tax contributions and other adjustments. Then choose the standard deduction, or enter your itemized total.
3. If they apply to you, add other deductions, tax credits, the federal tax already withheld and a state rate.
4. Read your estimated tax, bracket and effective rate. The table shows how much tax each bracket adds.

What the inputs mean

Gross income for the year

All your regular income for the year: wages, salary, bonuses, interest, taxable retirement withdrawals and similar. Long-term capital gains and qualified dividends are taxed at lower rates. Use the capital gains calculator for those.

Pre-tax contributions and adjustments (optional)

Amounts that come off your income first, leaving your adjusted gross income (AGI). They include traditional 401(k) and 403(b) contributions already left off your W-2, HSA contributions and deductible IRA contributions. Student loan interest and half of any self-employment tax count too.

Boxes checked for age 65+ or blind (optional)

Being 65 or older, or blind, makes your 2026 standard deduction bigger. It grows by $2,050 for each box checked on a single or head-of-household return, and by $1,650 per box for married filers. You get one box for being 65 or older and one for being blind. Each spouse counts separately.

Total itemized deductions

The total from Schedule A, the IRS form where you list deductions one by one. Itemizing only helps when this total is bigger than your standard deduction.

Other deductions (optional)

Deductions you can take on top of the standard or itemized amount. Examples are the qualified business income deduction and the new deductions for tips, overtime premiums (the extra pay above your normal rate) and people 65 and older. Enter the dollar amount you qualify for.

Tax credits (optional)

Credits cut the tax itself, dollar for dollar. That makes a credit worth more than a deduction of the same size. Here, credits can bring your tax down to zero, but not below.

Federal tax already withheld or paid (optional)

The federal income tax shown on your pay stubs or W-2, plus any estimated payments you made for 2026.

State income tax rate (optional)

One flat rate, applied to your income after adjustments.

Formula and method

adjusted gross income = gross income − adjustments
deduction = 2026 standard deduction (+ age 65 / blind amounts)  or  itemized total
taxable income = max(0, AGI − deduction − other deductions)
tax = Σ bracket rate × income falling inside that bracket
federal income tax = max(0, tax − credits)
effective rate = federal income tax ÷ gross income

In the formulas, AGI is your adjusted gross income, Σ means "add up", and max(0, …) means the answer can't go below zero. The 2026 standard deduction is $16,100 for single filers and for married people filing separately. It's $24,150 for heads of household and $32,200 for married couples filing jointly.

For a single filer, the 2026 rates on taxable income are 10% up to $12,400, 12% up to $50,400, 22% up to $105,700 and 24% up to $201,775. Above that come 32% up to $256,225, 35% up to $640,600 and 37% on the rest. Joint filers' brackets are about twice as wide.

Each rate applies only to the income inside its band. So earning one more dollar never leaves you worse off: only that dollar is taxed at the higher rate. Your marginal rate is the rate on your next dollar. Your effective rate is your total tax divided by your total income.

Worked example

A single filer earns $75,000 in 2026 and takes the standard deduction, with no adjustments or credits.

1. Taxable income: $75,000 − $16,100 = $58,900.
2. 10% on the first $12,400 = $1,240.
3. 12% on the next $38,000 (from $12,400 to $50,400) = $4,560.
4. 22% on the last $8,500 (from $50,400 to $58,900) = $1,870.
5. Total: $1,240 + $4,560 + $1,870 = $7,670.

Result: The estimated 2026 federal income tax is $7,670. The marginal rate is 22%, but the effective rate is only 10.23% of gross income.

Understanding the result

Your bracket tells you what a small change costs or saves. In the example, a $1,000 raise adds $220 of federal tax. A $1,000 traditional 401(k) contribution saves $220.

Your effective rate shows how much of your income goes to tax overall. It's always lower than your bracket rate. That's because the standard deduction and the lower bands cover the first part of your income.

If you entered tax already withheld, a refund means too much was taken out, and a balance due means too little was. Either way, you can update your W-4, the form that tells your employer how much to withhold, to get closer to the estimate.

Assumptions and limitations

• It uses the tax year 2026 brackets, standard deduction and extra amounts for age 65 or blindness, as published by the IRS in Rev. Proc. 2025-32.
• All income is treated as ordinary income. Credits are treated as non-refundable: they can bring your tax down to zero, but they don't pay you anything beyond that.
• The state rate is one flat percent of adjusted gross income.
• This is an estimate for planning, not tax advice. Check your figures against the IRS instructions or with a tax professional before you file.
• Some taxes and rules aren't included: lower rates on long-term capital gains and qualified dividends, self-employment tax, and Social Security and Medicare. It also leaves out the net investment income tax and the alternative minimum tax.
• It doesn't model phase-outs, where specific deductions and credits shrink as income rises. Refundable credit payments aren't modeled either.
• Real state income taxes have their own brackets, deductions and credits. Some cities add their own tax, too.

Frequently asked questions

How this calculator is checked

Method: Progressive bracket calculation using the 2026 tax rate tables, standard deduction and additional standard deduction from IRS Rev. Proc. 2025-32 (figures in src/lib/finance/tax-2026.ts); tests check the published bracket base amounts. The calculation is covered by automated tests with known reference values and edge cases. Last updated 2026-10-18. Found a problem? Tell us.

Embed this calculator

Put this Income Tax Calculator on your own website or blog for free. Paste this code where you want it to appear: