US Income Tax Calculator (Federal)
Choose your tax year and filing status, then enter your taxable income to estimate your federal income tax, effective tax rate, and marginal tax bracket.
Reviewed by the ToolNestr Editorial Team — July 2026
How federal income tax is calculated
The US uses a progressive tax system where income is divided into brackets, each taxed at a different rate. Your total tax is the sum of the tax on each bracket layer. The formula for each bracket is: Tax = Σ (income_in_bracket × bracket_rate). Your effective tax rate is Total Tax / Total Income × 100, and your marginal rate is the highest bracket your income reaches.
This progressive system means that a raise or bonus is only taxed at your marginal rate on the additional dollars, not your entire income. Understanding marginal versus effective rates helps you make informed decisions about retirement contributions, additional income, and tax planning strategies throughout the year.
Worked example
A single filer with $75,000 in taxable income in 2025.
About federal income tax
The US federal income tax is the largest source of government revenue, funding defense, infrastructure, healthcare, education, and social programs. Understanding how your income is taxed helps you plan withholdings, estimate quarterly payments if self-employed, and evaluate the tax impact of financial decisions. Use the Paycheck Calculator for a full picture including FICA taxes and deductions, or the Sales Tax Calculator for state and local sales taxes.
How to use it
- Select your filing status (Single, Married Filing Jointly, or Head of Household).
- Enter your estimated taxable income (gross income minus deductions).
- View your estimated federal income tax, effective tax rate, and marginal bracket.
When to use this tool
Use this calculator when preparing your tax return to estimate what you owe, when planning withholding on a new W-4, when considering a job offer in a different salary range, or when evaluating the tax impact of a bonus, side hustle, or investment sale. It is also useful for comparing how different filing statuses affect your tax liability.
Tips for tax planning
- Contribute to traditional retirement accounts (401k, IRA) to reduce your taxable income in your highest bracket.
- Consider Roth accounts if you expect to be in a higher tax bracket in retirement than you are now.
- Harvest investment losses to offset capital gains and up to $3,000 of ordinary income per year.
Salaried Employee
Estimate your annual tax liability and check whether your employer's withholding is on target. Avoid surprises at tax time by comparing estimated vs withheld amounts.
Freelancer / Self-Employed
Calculate estimated quarterly tax payments based on your projected annual income. Avoid underpayment penalties by knowing your tax liability in advance.
Newly Married Couple
Compare the tax impact of filing jointly versus separately. The marriage bonus or penalty varies by income levels — use this tool to plan your filing strategy.
Side Hustler
Estimate how much additional tax your side hustle income will generate. Know what to set aside for tax season so a side project doesn't become a tax burden.
How to use the income tax calculator
Choose your filing status
Select the status that matches your situation — this determines which bracket thresholds the calculator uses to compute your tax.
Enter your taxable income
This is your gross income minus the standard or itemized deduction. For a quick estimate, subtract the standard deduction from your expected gross income.
Review your results
See your total estimated tax, effective rate (what you actually pay on average), and marginal bracket (the rate on your next dollar earned).
Tips for reducing your tax bill
Maximize retirement contributions
Contributions to traditional 401k and IRA accounts reduce your taxable income dollar-for-dollar in the year you contribute. In 2025, you can contribute up to $23,500 to a 401k ($31,000 if over 50) and $7,000 to an IRA ($8,000 if over 50).
Use tax-advantaged accounts
HSAs (Health Savings Accounts) offer a triple tax advantage — contributions are tax-deductible, growth is tax-free, and withdrawals for qualified medical expenses are tax-free. FSAs also reduce taxable income for healthcare and dependent care costs.
Itemize when beneficial
If your deductible expenses (mortgage interest, state and local taxes up to $10,000, charitable donations, medical expenses exceeding 7.5% of AGI) exceed the standard deduction, itemizing reduces your taxable income further.
Related tools
- Paycheck Calculator — Calculate net pay after federal tax, FICA, state tax, and all deductions.
- Sales Tax Calculator — Estimate sales tax on purchases for any state and local jurisdiction.
- State Income Tax Calculator — Many states have their own income tax; check state-specific calculators for a complete picture.
Frequently asked questions
How do US federal income tax brackets work?
The US uses a progressive tax system with marginal brackets. Income is taxed in layers — the first portion is taxed at the lowest rate, and only income above each threshold is taxed at the next higher rate. Your marginal rate is the highest bracket your income reaches.
What is the difference between marginal and effective tax rate?
Your marginal tax rate is the rate applied to your last dollar of income (your highest bracket). Your effective tax rate is the total tax you pay divided by your total income — it is always lower than your marginal rate because of the progressive bracket structure.
Does this calculator account for deductions?
This calculator estimates federal income tax on taxable income, which is your gross income minus deductions (standard or itemized). For a rough estimate, enter your expected taxable income after subtracting the standard deduction or your itemized deductions.
What are the 2025 federal income tax brackets?
The 2025 brackets for single filers are: 10% ($0-$11,925), 12% ($11,925-$48,475), 22% ($48,475-$103,350), 24% ($103,350-$197,300), 32% ($197,300-$250,525), 35% ($250,525-$626,350), and 37% (over $626,350). Married filing jointly has roughly double the thresholds.
What filing statuses are available?
There are five filing statuses: Single, Married Filing Jointly, Married Filing Separately, Head of Household, and Qualifying Surviving Spouse. This calculator supports Single, Married Filing Jointly, and Head of Household.
Does this include FICA taxes?
No, this calculator estimates federal income tax only. FICA taxes (Social Security and Medicare) are separate — 7.65% for employees, 15.3% for self-employed. Use our Paycheck Calculator for a comprehensive net pay estimate.
What is the standard deduction?
The standard deduction reduces your taxable income. For 2025, it is $15,000 for single filers, $30,000 for married couples filing jointly, and $22,500 for heads of household. You can take the standard deduction or itemize, whichever is larger.
How do capital gains affect my tax bracket?
Long-term capital gains have their own tax rates (0%, 15%, or 20%) and are stacked on top of ordinary income. They do not push ordinary income into higher brackets, but ordinary income can push capital gains into higher capital gains brackets.
What is the Alternative Minimum Tax (AMT)?
The AMT is a parallel tax system designed to ensure high-income taxpayers pay a minimum amount. It disallows certain deductions and exemptions. This calculator does not compute AMT, which may affect very high-income filers with many deductions.
How often do tax brackets change?
Tax brackets are adjusted annually for inflation by the IRS. The income thresholds typically increase each year. This calculator uses the most recent brackets, but always check the current IRS guidelines for the tax year you are filing.
Sources & references
This tool uses standard formulas and reference values from:
- • IRS — federal tax brackets, standard deduction and instructions for the tax year. irs.gov
- • U.S. SEC — Investor.gov, compound interest and investment reference material. investor.gov
- • Official national tax authority for the relevant country — link the exact rate schedule used.
Estimates only, not tax or financial advice. Confirm current figures with the official source or a qualified professional.