Federal Income Tax Calculator – 2026 Tax Brackets
Estimate your 2026 federal income tax, marginal and effective rates, and potential refund or amount owed. Enter your filing status, income, contributions, deductions, qualifying children, and tax withheld.
Estimate Your 2026 Federal Income Tax
Income Tax Formula
Where:
- \(T\) — taxable income; \(G\) — gross income.
- \(K\) — entered pre-tax 401(k) contributions; \(H\) — entered deductible HSA contributions; \(D\) — the selected standard or itemized deduction.
- \(P\) — income tax before credits; \(r_i\) — rate for bracket \(i\); \(b_i\) — its upper taxable-income limit, with \(b_0=0\) and the final limit extending without bound.
- \(A\) — tax after the simplified child credit; \(n\) — number of qualifying children under 17; \(W\) — federal tax already withheld; \(R\) — estimated refund if positive, or amount owed if negative.
The calculator applies each bracket rate only to taxable income within that bracket. It then subtracts a simplified, nonrefundable child credit of up to $2,200 per entered child.
Income Tax – Calculation Example
Example: A single filer has $85,000 in gross income, $5,000 in pre-tax 401(k) contributions, $2,000 in deductible HSA contributions, the 2026 standard deduction of $16,100, one qualifying child, and $10,500 in federal tax withheld.
\[T=\$85{,}000-\$5{,}000-\$2{,}000-\$16{,}100=\$61{,}900\]
\[P=(\$12{,}400\times10\%)+(\$38{,}000\times12\%)+(\$11{,}500\times22\%)=\$8{,}330\]
\[A=\$8{,}330-\$2{,}200=\$6{,}130,\qquad R=\$10{,}500-\$6{,}130=\$4{,}370\]
Result: Estimated tax after the child credit is $6,130, with a $4,370 estimated refund. The marginal rate is 22%, and the effective rate after credits is 7.21% of gross income.
How to use the calculator
- Choose your Filing status: Single, Married filing jointly, Married filing separately, or Head of household. This determines the brackets and standard deduction used.
- Enter Gross income before the pre-tax contributions you will enter below. If you are planning around a future pay change, the annual salary increment calculator can help estimate a revised salary figure.
- Enter Pre-tax 401(k) contributions and Deductible HSA contributions. Include only eligible amounts that have not already been subtracted from Gross income; otherwise, they would be counted twice.
- Select a Deduction type. Choose Standard deduction to use the calculator’s 2026 amount for your filing status. Choose Itemized deduction to reveal Itemized deduction amount and enter your estimated total.
- Enter the whole-number count of Qualifying children under 17, then enter Federal tax already withheld. The withholding figure affects the refund or amount owed, not the tax calculation itself.
- Review Taxable income, Income tax before credits, both rates, Tax after child credits, and Estimated refund or amount owed. The Tax by bracket table shows how the pre-credit tax was calculated.
Understanding your federal income tax estimate
This calculator estimates 2026 federal ordinary-income tax using progressive brackets. Your gross income is reduced by the entered pre-tax contributions and your chosen deduction, but taxable income cannot fall below zero. For 2026, the standard deduction used here is $16,100 for Single or Married filing separately, $32,200 for Married filing jointly, and $24,150 for Head of household.
A bracket rate does not apply to all your income. If a single filer has $61,900 of taxable income, for example, the first $12,400 is taxed at 10%, the next $38,000 at 12%, and the remaining $11,500 at 22%. The displayed marginal tax rate is the rate that would apply to the next dollar of taxable income. At zero taxable income, the calculator displays a 0% marginal rate.
The effective tax rate after credits is tax after the simplified child credit divided by gross income, expressed as a percentage. It can be much lower than the marginal rate because lower brackets and the credit reduce total tax. It is not a percentage of taxable income. A refund means entered withholding exceeds estimated tax; an amount owed means estimated tax exceeds withholding. A refund is not an additional reduction in tax.
Assumptions and practical limits
The child credit is a simplified estimate: $2,200 per entered qualifying child under 17, limited to income tax before credits. The calculator does not test the child’s eligibility, apply income phase-outs, or calculate any refundable portion. Entering a child therefore does not guarantee that the same credit will appear on an actual return.
The estimate does not model capital gains rates, self-employment tax, alternative minimum tax, other taxes or credits, or additional adjustments and deductions. It also does not determine which expenses qualify as itemized deductions. If you are considering mortgage costs, the mortgage calculator can estimate payments, but a payment is not automatically a deductible expense.
Check that income, contributions, deductions, and withholding all refer to the same tax year. In particular, do not subtract a 401(k) or HSA contribution again if it is already excluded from the Gross income you entered. Use the result for planning, not as a substitute for a completed tax return or current IRS guidance. If you are planning what to do with a possible refund, the savings and investment calculator can model a separate savings goal.
Frequently Asked Questions
How can I calculate my 2026 federal income tax by hand?
First find taxable income, then tax only the portion that falls in each bracket. For example, a single filer with $30,000 of taxable income owes 10% on the first $12,400 and 12% on the remaining $17,600: $1,240 + $2,112 = $3,352 before credits. Subtract applicable credits to estimate income tax, then compare it with payments already made.
Should I enter my salary or the amount in Box 1 of my W-2?
Use a figure that lets you avoid subtracting the same contribution twice. W-2 Box 1 generally already excludes traditional 401(k) salary deferrals and qualifying HSA contributions made through payroll. If you start with Box 1, do not enter those excluded amounts again as contributions. If you start with salary before those deductions, enter eligible contributions separately. Other income and adjustments may also affect your actual return.
When is itemizing better than taking the standard deduction?
Itemizing generally reduces taxable income more when your allowable itemized deductions exceed the standard deduction for your filing status. Add only eligible expenses, subject to applicable limits, rather than using the full amount you spent. If you are married filing separately and your spouse itemizes, you generally cannot claim the standard deduction even if it would otherwise be larger. Check current IRS rules before choosing.
Does this estimate include Social Security and Medicare taxes?
No. Social Security and Medicare payroll taxes are separate from federal income tax and can still apply when your estimated income tax is zero. The federal tax withheld from a paycheck is also different from Social Security and Medicare withholding. Enter only federal income tax withholding in this calculator, not the combined total of all payroll taxes.
Where do I enter quarterly estimated tax payments?
There is no separate field for quarterly estimated payments. To get a rough refund or balance estimate, you can add federal estimated income tax payments to the amount entered as federal tax already withheld. This changes only the payment comparison, not the calculated tax. Your actual return may also account for other payments, refundable credits, and underpayment penalties that this calculator does not determine.
Can I get a refund if my calculated income tax is zero?
Yes, if you had federal income tax withheld, that withholding can be refunded even when this calculator estimates zero tax. Its simplified child credit cannot push tax below zero, however, and the estimate does not include refundable credits that might increase a real refund. A zero estimate also does not rule out other taxes on your return.
Do Roth 401(k) contributions reduce taxable income here?
No. Roth 401(k) contributions are generally made with after-tax dollars, so they do not reduce current-year federal taxable income the way traditional pre-tax 401(k) contributions generally do. Do not enter Roth contributions in the pre-tax 401(k) field. Employer contributions and contributions to other retirement accounts may follow different rules, so check how they are reported before adjusting your income.