How Taxes Work in United States of America
The United States uses a federal progressive income tax system with seven tax brackets ranging from 10% to 37%. In addition to federal taxes, most states impose their own income taxes, making your total tax burden highly dependent on where you live.
Employees also contribute to Social Security (6.2% up to the wage base limit) and Medicare (1.45%, plus an additional 0.9% on earnings above $200,000). These payroll taxes fund retirement benefits and healthcare for seniors.
The US tax system offers numerous deductions and credits including the standard deduction, 401(k) contributions, IRA contributions, HSA contributions, and child tax credits that can significantly reduce your effective tax rate.
Federal Tax Brackets
The US has seven federal income tax brackets: 10%, 12%, 22%, 24%, 32%, 35%, and 37%. Your marginal tax rate depends on your taxable income and filing status (single, married filing jointly, married filing separately, or head of household). Only income within each bracket is taxed at that rate, not your entire income.
State Income Taxes
State income taxes vary dramatically across the US. Nine states (Alaska, Florida, Nevada, New Hampshire, South Dakota, Tennessee, Texas, Washington, and Wyoming) have no state income tax. California has the highest top rate at 13.3%, while other states use flat rates. Your state of residence can make a difference of thousands of dollars per year.
Social Security & Medicare
FICA taxes include Social Security at 6.2% on earnings up to the annual wage base limit and Medicare at 1.45% on all earnings. High earners pay an additional 0.9% Medicare surtax on income above $200,000 (single) or $250,000 (married filing jointly). Self-employed individuals pay both the employee and employer portions.
Deductions & Retirement Accounts
Pre-tax contributions to 401(k) plans (up to $23,500 in 2025), traditional IRAs, and HSAs reduce your taxable income. The standard deduction for 2025 is $15,000 for single filers and $30,000 for married filing jointly. Itemizing deductions for mortgage interest, state taxes (capped at $10,000), and charitable contributions may be beneficial for some taxpayers.
Frequently Asked Questions
How much tax do I pay on a $100,000 salary in the US?
On a $100,000 salary as a single filer in 2025, you would pay approximately $14,768 in federal income tax using the standard deduction. Add FICA taxes (Social Security and Medicare) of about $7,650, and your total federal tax burden is roughly $22,418. State taxes vary — in Texas you would pay $0 in state tax, while in California you might owe an additional $5,000+.
What is the take-home pay on $80,000 in the United States?
On an $80,000 annual salary as a single filer with no state income tax, your approximate take-home pay is around $62,000 after federal income tax (~$10,168) and FICA taxes (~$6,120). In states with income tax like New York or California, your take-home would be $55,000-$58,000 depending on the state rate.
Which US states have no income tax?
Nine US states have no state income tax: Alaska, Florida, Nevada, New Hampshire (taxes only dividends and interest), South Dakota, Tennessee, Texas, Washington, and Wyoming. Moving to one of these states can save thousands of dollars annually in state taxes.
How do 401(k) contributions reduce my US taxes?
Traditional 401(k) contributions are made pre-tax, directly reducing your taxable income. For example, if you earn $100,000 and contribute $23,500 to your 401(k), you are only taxed on $76,500. At a 22% marginal rate, this saves you approximately $5,170 in federal taxes. Your 401(k) grows tax-deferred until withdrawal in retirement.
What is the difference between marginal and effective tax rate in the US?
Your marginal tax rate is the rate on your last dollar of income (the highest bracket you fall into), while your effective tax rate is the average rate you actually pay across all brackets. For example, a single filer earning $100,000 has a 22% marginal rate but an effective federal rate of about 15%. The effective rate is always lower because lower portions of income are taxed at lower brackets.