How federal income tax is actually calculated
Start with gross income, subtract pre-tax contributions and the standard deduction, and what remains is taxable income. The brackets then apply progressively: each rate charges only the dollars inside its own band. The result panel’s band table is the whole calculation made visible — there is nothing else in it.
taxable income = gross − pre-tax contributions − standard deduction; tax = Σ (band amount × band rate)Worked example · $75,000, single filer, 2026
- Taxable income: $75,000 − $16,100 standard deduction = $58,900.
- The first $12,400 is taxed at 10%, the next band at 12%, and the remainder at 22%.
- Total federal income tax: $7,670 — an effective federal rate of about 10.2%, though the marginal bracket is 22%.
Marginal versus effective, in one sentence each
Your marginal rate is the bracket your next dollar falls into — the number that matters when weighing extra income or a 401(k) contribution. Your effective rate is total tax divided by total income — the number that describes your year. The effective tax rate calculator puts the two side by side and explains the gap.
From tax owed to take-home pay
Income tax is the largest deduction for most earners, but not the only one. For the whole journey from gross salary to bank account — income tax, Social Security, Medicare and pre-tax contributions together — use the take-home pay calculator, or the salary after tax calculator for the full band-by-band tax story on a salary.
What’s included, and what isn’t
Every figure this calculator produces is an estimate. Here is exactly what it accounts for, and what it does not.
What’s included
- Federal income tax from the published brackets and standard deduction for your filing status.
- The full band-by-band working, so you can see which dollars are taxed at which rate.
- Your effective and marginal federal rates.
- Social Security and Medicare, shown alongside for the complete federal picture.
What’s not included
- State and local income taxes — this tool is federal only.
- Tax credits, itemised deductions and above-the-line adjustments other than the pre-tax contributions you enter.
- Capital gains, self-employment income and other income taxed under separate rules.
- Form W-4 withholding adjustments — this estimates the tax you owe, not what payroll deducts.
What this calculator assumes
- Uses the federal standard deduction for the selected filing status and tax year.
- Assumes W-2 employment at one job for the full calendar year.
- Pre-tax contributions reduce federal taxable income but not Social Security or Medicare wages.
- Social Security stops at the $184,500 wage base for 2026.
- Additional Medicare Tax follows the taxpayer's liability threshold for their filing status.
Sources
Every rate and threshold above is transcribed from a primary source and re-checked on the date shown.
Frequently asked questions
What are the federal tax brackets for 2026?
Seven rates — 10%, 12%, 22%, 24%, 32%, 35% and 37% — each applying only to the slice of taxable income inside its band. The thresholds differ by filing status and are set by the IRS in Rev. Proc. 2025-32; this calculator uses those published figures directly and shows which of your dollars fall where.
Do I pay my bracket's rate on all of my income?
No — this is the most common tax misconception. Being 'in the 22% bracket' means only the dollars above that band's threshold are taxed at 22%; everything below it is taxed at the lower bands' rates. That is why the effective rate in the result panel is always lower than the marginal bracket.
What is the standard deduction and how does it apply?
The amount subtracted from income before any bracket applies — $16,100 for single filers and $32,200 for joint filers in 2026. Income below it owes no federal income tax at all, though FICA still applies from the first dollar.
Does this include Social Security and Medicare?
They are shown alongside for the complete federal picture, but the headline figure is income tax alone. The FICA calculator isolates the payroll taxes if that is the number you need.
Is this what will be withheld from my paycheck?
Not exactly. This estimates the tax you owe for the year; payroll withholding follows your W-4 and can run higher or lower, with the difference settled at filing. The paycheck calculator models the withholding side.