What the calculation includes
The calculator applies the federal ordinary-income brackets for the selected year and filing status. It subtracts the larger of the base standard deduction or the itemized-deduction amount you enter. A supported Schedule 1-A deduction, when entered, is treated separately after AGI rather than as an itemized deduction.
Important exclusions
The result does not determine eligibility for a deduction, include additional standard-deduction amounts for age or blindness, apply the special standard-deduction rules for dependents, or calculate tax credits, payments, withholding, refundable amounts, self-employment tax, net investment income tax, alternative minimum tax, preferential capital-gain rates, or state and local tax.
Frequently asked questions
What does this federal income tax calculator estimate?
It estimates federal ordinary-income tax for 2025 or 2026 after the larger of the base standard deduction or your entered itemized deductions. The base amount excludes additions for age or blindness and special dependent rules. If entered, a supported Schedule 1-A deduction is applied separately. It does not calculate credits, withholding, refunds, self-employment tax, investment taxes, alternative minimum tax, or state tax.
Why does the calculator ask for adjusted gross income?
Adjusted gross income, or AGI, is income after certain adjustments and before the standard or itemized deduction. AGI is not the same as gross pay or taxable income. Use the AGI shown on the relevant return or a carefully prepared estimate.
Are Schedule 1-A deductions the same as itemized deductions?
No. Eligible Schedule 1-A deductions are claimed after AGI and may be available whether you take the standard deduction or itemize. Eligibility, caps, and income phaseouts still apply, and married filing separately is not eligible for these deductions.