How to Estimate Your Federal Income Tax Online
Most people have no clear idea what their federal tax bill will be until they file in April — and by then, adjusting withholding to avoid underpayment penalties is too late for that year. Understanding how federal income tax is calculated lets you estimate your liability throughout the year and make better financial decisions around deductions, retirement contributions, and income timing.
How US federal income tax brackets work
The US uses a marginal tax rate system — each dollar is taxed at the rate for the bracket it falls into, not a flat rate applied to your entire income. If you're in the 22% bracket, you don't pay 22% on all your income. You pay 10% on the first portion, 12% on the next portion, and 22% only on income above the 22% threshold.
For 2026, the federal income tax brackets for single filers are approximately: 10% on income up to $11,600; 12% on $11,601 to $47,150; 22% on $47,151 to $100,525; 24% on $100,526 to $191,950; 32% on $191,951 to $243,725; 35% on $243,726 to $609,350; 37% on income above $609,350. Married filing jointly has different thresholds. These adjust annually for inflation.
Standard deduction vs itemising
Your taxable income is your gross income minus deductions. Most taxpayers take the standard deduction — for 2026, approximately $14,600 for single filers and $29,200 for married filing jointly. This means a single filer with $60,000 income would have approximately $45,400 in taxable income after the standard deduction.
Itemising is only worthwhile if your total itemised deductions (mortgage interest, state taxes up to $10,000, charitable contributions, some medical expenses) exceed the standard deduction. Since the 2017 tax law doubled the standard deduction, most households take it rather than itemising.
Using the federal tax calculator
Enter your gross income, filing status, and any deductions or tax credits you're aware of. The calculator applies the current brackets and shows your estimated federal tax liability, effective tax rate, and marginal rate. This estimate doesn't include state income tax, FICA (Social Security and Medicare), or self-employment tax — those add separately.
A critical reminder: this is an estimate. Your actual liability depends on factors the calculator can't account for without your complete tax return. For tax advice specific to your situation, consult a tax professional or use IRS-approved tax software.
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Federal Tax Calculator
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Open Federal Tax Calculator →Frequently Asked Questions
How do US federal income tax brackets work?
The US uses marginal tax brackets — each portion of your income is taxed at the rate for that bracket, not your entire income. Being in the 22% bracket means you pay 22% only on income above the 22% threshold, not on everything you earned.
What is the standard deduction for 2026?
For 2026, approximately $14,600 for single filers and $29,200 for married filing jointly (amounts adjust annually for inflation). The standard deduction reduces your taxable income before calculating tax owed. Most taxpayers take the standard deduction rather than itemising.
What is my effective tax rate vs marginal tax rate?
Your marginal tax rate is the rate on your last dollar of income — the highest bracket you're in. Your effective tax rate is your total tax paid divided by your total income — a blended average across all brackets. Effective rates are always lower than marginal rates.
Does the federal tax calculator include state taxes?
No. Federal and state income taxes are separate systems with separate rates. The federal calculator estimates only your US federal tax liability. Add your state's income tax separately for a complete picture.
How do I reduce my federal income tax?
Maximise pre-tax retirement contributions (401k, IRA) which reduce taxable income. Contribute to an HSA if eligible. Track deductible business expenses if self-employed. Claim all applicable tax credits (child tax credit, education credits). Consult a tax professional for strategies specific to your situation.