US Federal Taxes Calculator (2024‑2025)

How this US federal taxes calculator works

This tool estimates your US federal income tax using the official IRS marginal tax brackets and standard deductions for the selected year. It applies the brackets to your taxable income and then subtracts any tax credits you enter.

Step 1 – Compute adjusted gross income (AGI)

We start from your total income and subtract any above‑the‑line adjustments you enter (for example, deductible traditional IRA contributions, HSA contributions, or student loan interest):

Step 2 – Subtract deductions

Next, we subtract either the standard deduction for your filing status and year, or the custom itemized deduction amount you provide:

If you choose “Standard deduction”, the calculator automatically fills in the correct amount for your filing status and tax year and keeps it in sync when you change either one.

Step 3 – Apply the marginal tax brackets

US federal income tax is progressive: different slices of your taxable income are taxed at different rates. For each bracket:

1. We determine how much of your taxable income falls into that bracket.
2. We multiply that slice by the bracket’s tax rate.

The total tax before credits is the sum of tax from all brackets:

Step 4 – Subtract tax credits

Finally, we subtract any tax credits you enter (for example, child tax credit, American Opportunity credit, Lifetime Learning credit):

Effective vs. marginal tax rate

• Marginal tax rate – the rate that applies to your last dollar of taxable income. This is determined by the highest bracket you reach.
• Effective tax rate – your total federal tax divided by your total income:

  Effective rate = Federal tax ÷ Total income

Because the US system is progressive, your effective tax rate is always lower than your top marginal rate.

Limitations and what’s not included

This calculator is designed for clarity and quick planning. It does not model every detail of the Internal Revenue Code. In particular, it does not:

• Compute Alternative Minimum Tax (AMT).
• Handle the Net Investment Income Tax (NIIT) or additional Medicare surtaxes.
• Apply phase‑outs for specific credits or deductions.
• Calculate self‑employment tax or the qualified business income (QBI) deduction.
• Include state or local income taxes or payroll (Social Security and Medicare) taxes.

For complex situations, high incomes, or business owners, you should confirm results with a tax professional or official IRS tools and publications.

Frequently asked questions

Is this calculator the same as filing my tax return?

No. This is an educational and planning tool. It uses the current IRS brackets and standard deductions to give you a realistic estimate, but it does not replace official tax preparation software or professional advice.

Which filing status should I choose?

• Single – generally if you are unmarried and do not qualify for another status.
• Married filing jointly (MFJ) – most married couples use this status.
• Married filing separately (MFS) – sometimes used when one spouse has large medical expenses or liability concerns.
• Head of household (HoH) – unmarried, paid more than half the cost of keeping up a home, and have a qualifying person living with you.

How accurate is the estimate?

For many wage‑earning households that take the standard deduction and have straightforward finances, this calculator will usually be in the right ballpark. The more special rules, credits, or business income you have, the more your actual tax may differ.

Where can I see the official IRS brackets?

The IRS publishes the official federal income tax rates, brackets, and standard deductions each year in Revenue Procedure documents and on the IRS website. You can also find detailed explanations in IRS Publication 17 and the instructions for Form 1040.