What This Calculator Estimates
US Federal Income Tax is administered by the IRS using a progressive bracket system, where different portions of taxable income are taxed at increasing marginal rates, after accounting for the standard deduction or itemized deductions. Because brackets are adjusted annually for inflation and can change with tax legislation, this calculator uses an editable rate so you can model your specific marginal bracket rather than relying on a fixed figure that may not reflect the current tax year.
How to Use This Calculator
- Enter taxable income.
- Enter an estimated federal tax rate.
- Click Estimate Federal Tax.
- Review the estimated tax and after-tax income.
- Verify official rules before relying on the result.
Related Calculators
Taxable Income Calculator · Tax Bracket Calculator · Tax Refund Estimator
Tips for a More Accurate Estimate
- Apply your standard or itemized deduction to gross income before estimating taxable income.
- Remember only income within each bracket is taxed at that bracket's rate — not your whole income.
- Check your filing status (single, married filing jointly, etc.), since brackets differ by status.
- Recheck IRS bracket tables each tax year, since thresholds adjust for inflation.
- Consider using this alongside a state income tax calculator for your total tax picture.
Frequently Asked Questions
How does the US federal progressive bracket system work?
Only the portion of income within each bracket is taxed at that bracket's rate — your entire income isn't taxed at your top marginal rate, which is a common misconception.
What's the difference between marginal rate and effective rate?
Your marginal rate is the rate applied to your last dollar of income, while your effective rate is your total tax divided by total income — the effective rate is almost always lower than the marginal rate.
Does this calculator apply the standard deduction automatically?
No, subtract your applicable standard or itemized deduction from gross income before entering a taxable income figure, or adjust your rate to reflect your effective burden.
How often does the IRS adjust tax brackets?
The IRS adjusts bracket thresholds annually for inflation, and brackets themselves can change through tax legislation — check the current tax year's published brackets.
Where can I confirm current official federal brackets?
The IRS publishes current tax bracket tables for each filing status on its official website.
Last updated: May 11, 2026