How Progressive Taxation Works
The US federal income tax is a progressive tax system, meaning higher levels of income are taxed at higher rates. But there is a pervasive and consequential misunderstanding about how this works: your tax bracket does not apply to all of your income. It applies only to the portion of your income that falls within that bracket.
Think of it as a series of buckets. The first bucket covers income from $0 up to the top of the 10% bracket. Every dollar in that bucket is taxed at 10%. The second bucket covers income above the 10% threshold up to the top of the 12% bracket — every dollar in that bucket is taxed at 12%, regardless of the taxpayer's total income. This pattern continues up through the brackets. Your "tax bracket" is simply the rate applied to your highest dollars — it tells you nothing about the rate applied to your lower-earning dollars.
This is why effective tax rates are always lower than marginal rates. A single filer earning $85,000 in 2026 is in the 22% marginal bracket — but they pay 10% on their lowest dollars, 12% on middle dollars, and 22% only on the top portion. The blended rate across all their income (effective rate) comes out to about 11–12%, far below the 22% that people often assume applies to everything.
The Standard Deduction: First, Reduce Your Taxable Income
Before any bracket calculations occur, the IRS allows most taxpayers to subtract the standard deduction from their gross income. The standard deduction is a flat dollar amount set each year by Congress and adjusted annually for inflation. For 2026, it is $16,100 for single filers and $32,200 for married couples filing jointly (per IRS Rev. Proc. 2025-32).
The standard deduction effectively creates a zero-tax zone at the bottom of your income. A single filer earning $16,100 or less in 2026 pays zero federal income tax — not because they're in a 0% bracket, but because the standard deduction zeroes out their taxable income before brackets even apply.
Taxpayers may also choose to itemize deductions (mortgage interest, state taxes up to the $10,000 SALT cap, charitable contributions, etc.) if their itemized total exceeds the standard deduction. Most taxpayers take the standard deduction because the 2017 tax law significantly increased it. The Tax Cuts and Jobs Act of 2017 roughly doubled the standard deduction, causing the fraction of taxpayers who itemize to drop from about 30% to below 10%.
Worked Example: $85,000, Single, 2026
Gross income: $85,000 | Filing status: Single | Tax year: 2026
Step 1 — Apply standard deduction:
Taxable income = $85,000 − $16,100 = $68,900
Step 2 — Apply brackets to taxable income (2026 single brackets):
10% bracket: $0 – $12,400 → $12,400 × 10% = $1,240
12% bracket: $12,400 – $50,400 → $38,000 × 12% = $4,560
22% bracket: $50,400 – $68,900 → $18,500 × 22% = $4,070
(Income stops at $68,900; 24% and higher brackets are not reached)
Total federal income tax: $1,240 + $4,560 + $4,070 = $9,870
Effective tax rate: $9,870 / $85,000 = 11.61%
Marginal tax rate: 22% (the bracket the last dollar falls into)
Estimated take-home: $85,000 − $9,870 = $75,130 / year = $6,261 / month
Note: This does not include FICA taxes (7.65% = $6,503) or state income tax.
The key takeaway: this filer is "in the 22% bracket," but their effective rate is only 11.61%. They pay 22 cents on the dollar only for the $18,500 of income above $50,400 — not on any dollar below that threshold. This is the core mechanic that makes the progressive system function differently from what most people assume.
Marginal Rate vs. Effective Rate: Why Both Matter
These two numbers answer different questions, and knowing which question you're asking matters enormously.
Effective tax rate answers: "What fraction of my total income goes to federal income tax?" It's the number to use when thinking about your overall tax burden, comparing tax burdens across different income levels, or understanding how much of your paycheck goes to the IRS on average. It is calculated as total federal income tax / gross income.
Marginal tax rate answers: "If I earn one more dollar, how much of it goes to federal income tax?" It's the number to use when making decisions at the margin: Should I take on freelance work? Does it make sense to convert a traditional IRA to Roth? How much does a year-end bonus actually add to my take-home? Should I maximize my 401(k) to drop into a lower bracket? The marginal rate is the relevant rate for any incremental income decision.
A common error is using the marginal rate to calculate total tax burden ("I'm in the 22% bracket so I owe 22% of my income"), which consistently overestimates the actual tax owed. Equally, using only the effective rate when evaluating marginal decisions ("I'm in the 11% effective bracket so another $10,000 of consulting income costs me $1,100 in tax") consistently underestimates the marginal tax cost.
What This Calculator Does NOT Include
- FICA Taxes (Social Security + Medicare): Employees pay 6.2% for Social Security (on wages up to $168,600 in 2024) and 1.45% for Medicare (no cap) — a combined 7.65%. Self-employed individuals pay 15.3% (both employer and employee share). These are entirely separate from federal income tax.
- State Income Tax: Most states impose their own income tax, ranging from 0% (Alaska, Florida, Nevada, New Hampshire, South Dakota, Tennessee, Texas, Washington, Wyoming) to over 13% (California). This can significantly change your total tax burden.
- Alternative Minimum Tax (AMT): Some higher-income taxpayers may owe AMT, which is calculated separately and applies if it exceeds the regular tax. This calculator does not compute AMT.
- Tax Credits: The Child Tax Credit, Earned Income Tax Credit (EITC), Child and Dependent Care Credit, education credits, and many others directly reduce the tax owed (not just taxable income). This calculator applies no credits.
- Capital Gains: Long-term capital gains from stocks, real estate, and other assets are taxed at 0%, 15%, or 20% depending on income — separate from ordinary income tax rates. Short-term capital gains (held less than one year) are taxed as ordinary income.
- Itemized Deductions: If your total itemized deductions (mortgage interest, state taxes up to $10,000 SALT cap, charitable contributions, etc.) exceed the standard deduction, you would use itemized deductions instead, which this calculator does not model.
How Tax Brackets Are Adjusted for Inflation
Each year, the IRS adjusts tax brackets, standard deductions, and dozens of other thresholds using a formula tied to the Chained CPI (C-CPI-U). This prevents "bracket creep" — the phenomenon where inflation pushes workers into higher tax brackets even though their real purchasing power hasn't changed.
The IRS publishes these adjustments each October in a Revenue Procedure document. For 2026 brackets, the relevant publication is IRS Rev. Proc. 2025-32, issued on October 9, 2025. For 2025, it was Rev. Proc. 2024-40. For 2024, it was Rev. Proc. 2023-34. These documents are public and available at IRS.gov.
2024: $14,600 (per IRS Rev. Proc. 2023-34)
2025: $15,750 (per IRS Rev. Proc. 2024-40, as amended by OBBBA July 2025) — increase of $1,150 (+7.9%)
2026: $16,100 (per IRS Rev. Proc. 2025-32) — increase of $350 (+2.2%)
The large 2025 increase reflects the One Big Beautiful Bill Act (OBBBA), signed July 2025, which retroactively raised the 2025 standard deduction above the original inflation-indexed figure.
Inflation indexing means that if your salary grew by exactly the rate of inflation, you would pay roughly the same effective tax rate year over year — the brackets move up with prices, keeping the real (inflation-adjusted) burden roughly constant. If your salary grows faster than inflation, you will pay a slightly higher effective rate; if slower, slightly lower. This is by design — the system aims to be neutral to inflation in terms of real tax burden.
When to Know Your Effective vs. Marginal Rate
Use your effective rate when: Comparing your overall tax burden to others. Budgeting annual take-home pay. Discussing what percentage of income goes to taxes in a general sense. Understanding your total tax picture relative to income.
Use your marginal rate when: Deciding whether to contribute to a traditional vs. Roth retirement account (traditional reduces taxable income at your marginal rate; Roth provides tax-free growth). Evaluating a year-end bonus or freelance project. Considering tax-loss harvesting. Determining the benefit of deductible expenses like mortgage interest or charitable donations. Any decision that changes income by a bounded amount.
Frequently Asked Questions
Your marginal rate is the rate applied to your last (highest) dollar of income — the top bracket you enter. Your effective rate is total federal income tax divided by gross income — the average across all your income. Because the US uses progressive brackets, you pay lower rates on your lower income and higher rates only on your highest income. The result is that effective rates are always lower than marginal rates. For example, a single filer with $85,000 in income in 2026 has a 22% marginal rate but pays only about 11.6% effective — because the 22% applies only to about $18,500 of their income, not all $85,000.
The 2026 federal income tax brackets for single filers (per IRS Rev. Proc. 2025-32) are: 10% on taxable income up to $12,400; 12% from $12,400 to $50,400; 22% from $50,400 to $105,700; 24% from $105,700 to $201,775; 32% from $201,775 to $256,225; 35% from $256,225 to $640,600; 37% above $640,600. Married filing jointly thresholds are approximately double the single filer thresholds. The standard deduction is $16,100 for single filers and $32,200 for MFJ. These amounts are subtracted from gross income before applying any brackets.
This estimator calculates federal income tax on ordinary income assuming the standard deduction. Your actual tax bill may differ for many reasons: you may itemize deductions (mortgage interest, state taxes, charitable contributions); you may have tax credits (child tax credit, EITC, education credits) that reduce tax dollar-for-dollar; you may have capital gains taxed at lower rates; you may owe AMT; you may have business income with different treatment; or your state may have additional taxes. This tool is designed for educational estimates and general awareness, not as a substitute for proper tax preparation software or a CPA.
IRS Revenue Procedure 2025-32 is the official IRS publication that sets the inflation-adjusted tax parameters for tax year 2026, including bracket thresholds, standard deduction amounts, and dozens of other inflation-indexed figures. It was issued on October 9, 2025. "Rev. Proc." is short for Revenue Procedure — a type of IRS guidance document. Rev. Proc. 2024-40 covered 2025, and Rev. Proc. 2023-34 covered 2024. These documents are publicly available at IRS.gov and are the authoritative source for the bracket data used in this calculator.
No. FICA (Federal Insurance Contributions Act) taxes — Social Security at 6.2% and Medicare at 1.45% — are entirely separate from federal income tax and are not included in this estimator. For 2024, Social Security applies to wages up to $168,600; Medicare has no wage cap. Employees pay the combined 7.65% rate; self-employed individuals pay 15.3% (covering both the employee and employer share). If you want to estimate your total federal tax burden including FICA, add approximately 7.65% to your estimated income tax for wage earners.
The standard deduction is a flat dollar amount that taxpayers can subtract from their gross income before applying tax brackets. It represents an approximation of typical deductible expenses and is available to all taxpayers who don't choose to itemize. For 2026: single filers and married filing separately can deduct $16,100; married filing jointly can deduct $32,200; head of household can deduct $24,150. The standard deduction means that no federal income tax is owed on the first $16,100 of income (for a single filer in 2026), since that income is entirely offset before brackets are applied.
The IRS adjusts tax brackets annually using the Chained Consumer Price Index (C-CPI-U), published by the Bureau of Labor Statistics. The C-CPI-U is slightly different from the standard CPI-U — it accounts for consumers substituting toward cheaper alternatives when prices rise, which generally makes it grow slightly slower than the regular CPI. Each October, the IRS publishes a Revenue Procedure that specifies the adjusted brackets for the following tax year. This annual indexing is designed to prevent "bracket creep," where inflation alone pushes workers into higher brackets even though their real income hasn't increased.