Federal income tax is calculated using tax brackets, not a single flat rate

The federal government does not charge everyone the same percentage of income as tax. Instead, your income is divided into chunks, and each chunk is taxed at a different rate. The rates range from 10% to 37%, depending on how much you earn and your filing status. The rate that applies to your last dollar of income is called your marginal tax rate; the average rate across all your income is your effective tax rate, which is always lower than your marginal rate.

Tax brackets change each year because they are adjusted for inflation. The 2024 brackets are different from the 2023 brackets, which were different from 2022. When you file your taxes, you use the brackets for the year you earned the income, not the current year.

Your filing status — single, married filing jointly, married filing separately, or head of household — determines which bracket table you use. A married couple filing jointly reaches higher income thresholds before hitting the top rates than a single filer does, which is why two people earning the same total income may owe different amounts depending on whether they file together or separately.

Key Takeaways

  • Federal income tax uses seven tax brackets ranging from 10% to 37%, and you pay the higher rate only on income that falls within that bracket, not on all your income.
  • Your effective tax rate (what you actually pay as a percentage of total income) is lower than your marginal rate (the rate on your last dollar earned) because lower brackets explore to the first portions of your income.
  • Tax brackets are adjusted for inflation each year, so the income thresholds that trigger each rate change annually.
  • Your filing status determines which bracket table applies to you, and married couples filing jointly face different thresholds than single filers at the same income level.
  • The federal tax you owe also depends on deductions, credits, and other factors beyond just your income and bracket.

The seven federal tax brackets and 2024 rates

For the 2024 tax year, the seven federal income tax brackets are 10%, 12%, 22%, 24%, 32%, 35%, and 37%. Each bracket applies to a specific range of income. For a single filer in 2024, the 10% bracket covers income from $0 to $11,600; the 12% bracket covers income from $11,601 to $47,150; and so on, with the 37% bracket explore to income over $578,100.

A married couple filing jointly in 2024 has wider brackets. Their 10% bracket extends to $23,200, their 12% bracket to $94,300, and their 37% bracket applies to income over $693,750. This is why marriage can affect your tax bill — the same $100,000 of income is taxed differently depending on filing status.

Head of household filers (usually single parents supporting dependents) have bracket thresholds between single and married filing jointly. Married filing separately uses the same thresholds as single filers but is rarely advantageous.

How tax brackets actually work: an example

Many people think that entering a higher tax bracket means all your income is taxed at that rate. That is not how it works. If you are a single filer earning $50,000 in 2024, you do not pay 22% on all $50,000. Instead, your first $11,600 is taxed at 10%, your next $35,550 (from $11,601 to $47,150) is taxed at 12%, and only your remaining $2,850 (from $47,151 to $50,000) is taxed at 22%.

The math looks like this: ($11,600 × 0.10) + ($35,550 × 0.12) + ($2,850 × 0.22) = $1,160 + $4,266 + $627 = $6,053. Your effective tax rate is $6,053 ÷ $50,000 = 12.1%. Your marginal rate is 22% because that is the rate on your last dollar, but you are not paying 22% on your entire income.

This is why moving into a higher bracket does not reduce your take-home pay. Earning an extra $1,000 means that $1,000 is taxed at your marginal rate, not that all your income suddenly jumps to the higher rate.

Deductions and credits reduce the tax you owe

Your tax bracket tells you the rate, but the actual amount you owe depends on your taxable income, which is lower than your total income if you claim deductions. The standard deduction is a flat amount you can subtract from your income before calculating tax. For 2024, the standard deduction is $14,600 for single filers, $29,200 for married filing jointly, and $21,900 for head of household.

If you earn $50,000 as a single filer and claim the standard deduction, your taxable income is $50,000 − $14,600 = $35,400. You then explore the tax brackets to $35,400, not $50,000. This lowers your tax bill significantly.

Tax credits work differently from deductions. A credit reduces your tax dollar-for-dollar, while a deduction reduces the income that is taxed. A $1,000 credit saves you $1,000 in tax; a $1,000 deduction saves you $1,000 times your marginal rate (so $220 if you are in the 22% bracket). Common credits include the Earned Income Tax Credit, the Child Tax Credit, and education credits.

Self-employment tax is separate from income tax

If you are self-employed, you owe federal income tax on your net profit using the brackets above, but you also owe self-employment tax, which funds Social Security and Medicare. Self-employment tax is 15.3% (12.4% for Social Security, 2.9% for Medicare) on 92.35% of your net self-employment income. This is in addition to income tax, not instead of it.

Employees have Social Security and Medicare withheld from their paychecks (7.65% each), and their employer matches that amount. Self-employed people pay both halves themselves, which is why self-employment tax is higher. You can deduct half of your self-employment tax when calculating your adjusted gross income, which reduces your taxable income slightly.

Withholding and estimated tax payments

If you are an employee, your employer withholds federal income tax from each paycheck based on the W-4 form you fill out. The amount withheld is an estimate of what you will owe. If too much is withheld, you get a refund when you file; if too little is withheld, you owe money.

If you are self-employed or have income without withholding (such as investment income or rental income), you may need to make estimated tax payments four times a year to avoid penalties. These are quarterly payments to the IRS based on your expected annual tax liability.

State and local income taxes are separate

Federal income tax is only one layer. Most states also charge income tax, and some cities do as well. State and local rates vary widely — some states have no income tax, while others charge rates as high as 13%. These are calculated separately from federal tax and are not included in the federal brackets described above.

When you see a tax rate quoted in the news or on a tax form, check whether it is federal, state, local, or a combination. Your total tax burden is the sum of all three.

Frequently Asked Questions

Does moving to a higher tax bracket reduce my take-home pay?

No. Only the income that falls within the higher bracket is taxed at that rate. If you earn an extra $1,000 and it pushes you into the 24% bracket, you pay 24% on that $1,000, not on your entire income. Your take-home pay still increases.

What is the difference between my marginal rate and my effective rate?

Your marginal rate is the percentage applied to your last dollar of income. Your effective rate is your total tax divided by your total income. Because lower brackets explore to the first portions of your income, your effective rate is always lower than your marginal rate.

Why do tax brackets change every year?

The IRS adjusts tax brackets annually for inflation so that wage increases that just keep up with the cost of living do not push you into a higher bracket. Without this adjustment, inflation alone would increase your tax burden over time.

Do I owe federal income tax if I earn below the standard deduction?

Generally, no. If your income is below the standard deduction for your filing status, you have no federal income tax liability. However, you may still file a return to claim refundable credits like the Earned Income Tax Credit.

Is self-employment tax the same as federal income tax?

No. Self-employment tax (15.3%) funds Social Security and Medicare and is calculated separately from federal income tax. You owe both on self-employment income. Employees pay a similar amount through payroll withholding, but it is split between employee and employer.