Income Tax Calculator
Work out your 2024 federal income tax the way the IRS actually calculates it — bracket by bracket — plus your taxable income, effective rate and marginal rate.
Standard deduction: $14,600 (Single, 2024)
On-screen number pad
| Bracket | Rate | Taxed in this bracket |
|---|
Step-by-step proofCheck by hand
How each bracket is taxed
Each bar is the tax owed from that bracket alone. Only the top bar — the bracket your last dollar falls into — is taxed at your marginal rate; every bar below it is a lower rate.
How federal income tax is calculated
US federal income tax is a marginal, or progressive, tax: income is divided into brackets, and each bracket's rate applies only to the slice of income that falls inside it. Moving into a higher bracket does not raise the rate on income you already earned — it only raises the rate on the additional income that pushed you into it.
Taxable income is gross income minus pre-tax contributions (like a 401(k)) minus a deduction — either the standard deduction, a fixed amount set annually by filing status, or the sum of itemized deductions if that total is larger. Tax is then calculated bracket by bracket on the taxable income, not the gross income.
The method
Summed across every bracket the taxable income reaches — not one single rate applied to the whole amount.
Worked example
A single filer earning $75,000 with no pre-tax contributions, taking the $14,600 standard deduction, has $60,400 in taxable income. The first $11,600 is taxed at 10% ($1,160), the next $35,550 at 12% ($4,266), and the remaining $13,250 at 22% ($2,915) — a total of $8,341. That's a 22% marginal rate but only a 13.8% effective rate.
Frequently asked questions
Why is my tax bill lower than income × my tax bracket?
What's the difference between my effective rate and my marginal rate?
Should I use the standard deduction or itemize?
Does this include Social Security and Medicare tax?
- 2024 federal income tax brackets and standard deductions — IRS Revenue Procedure 2023-34 (rates and thresholds set annually; verify the current tax year's figures at irs.gov before filing).
- Marginal (progressive) tax calculation — general published US federal tax law; the IRS's own Tax Withholding Estimator and Publication 17 describe the same bracket-by-bracket method.