What Gets Taken Out of Your Paycheck

Your employer withholds taxes from each paycheck based on information you provided on your W-4 form when you were hired. The amount depends on your filing status, the number of dependents you claim, and your expected annual income. Federal income tax, Social Security tax (6.2%), and Medicare tax (1.45%) are the three main deductions. Your state may also withhold state income tax, and some cities withhold local income tax.

The federal income tax withheld is not a fixed percentage—it varies based on your tax bracket and how much you've already paid that year. Social Security and Medicare are flat percentages applied to your gross pay, with no upper limit on Medicare but a wage cap on Social Security (the cap changes yearly). Your employer matches the Social Security and Medicare amounts, but that money does not come from your paycheck.

Key Takeaways

  • Federal income tax withholding depends on your W-4 answers, not a single percentage, and changes if you update your W-4 during the year.
  • Social Security tax is always 6.2% of your gross pay up to an annual wage cap, and Medicare tax is always 1.45% with no cap.
  • Your actual tax bill at the end of the year may be higher or lower than what was withheld, so you may owe money or receive a refund.
  • You can use the IRS Withholding Estimator or a paycheck calculator to see whether your withholding is roughly correct for your situation.

How Federal Income Tax Withholding Works

Federal withholding is calculated using IRS tables that account for your pay frequency (weekly, biweekly, monthly), your filing status, and the number of allowances or dependents you claimed on your W-4. The IRS publishes updated tables each year. Your employer's payroll system looks up your pay amount in the correct table and subtracts the amount shown.

The withholding is designed to spread your annual tax liability across each paycheck so you do not owe a large amount in April. If you claim zero allowances, more tax is withheld. If you claim more allowances, less is withheld. The number of allowances does not directly equal the number of dependents—it is a separate calculation that accounts for your filing status and other factors.

If your life changes during the year (you get married, have a child, take a second job, or your spouse starts working), you should update your W-4 so your withholding stays accurate. Without an update, you may have too much or too little withheld for the rest of the year.

Calculating Social Security and Medicare Taxes

These two taxes are straightforward percentages with no variation based on your answers or filing status. Social Security tax is 6.2% of your gross pay, but only up to a wage cap set by the government each year. Once you earn more than the cap in a calendar year, no more Social Security tax is withheld from that year's paychecks. The cap changes yearly—for example, in 2024 the cap was $168,600, meaning no Social Security tax was withheld on earnings above that amount.

Medicare tax is 1.45% of your gross pay with no wage cap. If your income exceeds certain thresholds (which vary by filing status), an additional 0.9% Medicare tax is withheld on the excess. For single filers in 2024, that threshold was $200,000. This additional tax is withheld automatically once you cross the threshold, with no W-4 adjustment needed.

To calculate these by hand, multiply your gross pay by the percentage. For example, if you earn $2,000 in a biweekly paycheck and have not yet hit the Social Security wage cap, your Social Security tax is $2,000 × 0.062 = $124. Your Medicare tax is $2,000 × 0.0145 = $29.

State and Local Income Tax Withholding

Forty-one states and the District of Columbia have state income tax. Nine states have no state income tax at all: Alaska, Florida, Nevada, South Dakota, Tennessee, Texas, Washington, Wyoming, and New Hampshire (which taxes only dividends and interest, not wages). If you live in a state with income tax, your employer withholds based on a state W-4 form you filled out, similar to the federal form.

State withholding rates and rules vary widely. Some states use a flat percentage, while others use tax brackets like the federal system. A few cities—including New York City, Philadelphia, and Columbus—also withhold local income tax. Your pay stub will show each withholding separately so you can see what goes to federal, state, and local taxes.

Understanding Your Pay Stub

Your pay stub lists your gross pay (total earnings before any deductions), then shows each tax withheld, then shows your net pay (take-home amount). The stub also shows year-to-date totals, which tell you how much you have earned and how much tax you have paid so far this year. These year-to-date numbers are important when you file your tax return, because they show your total income and total withholding.

Common deductions on a pay stub include federal income tax (labeled FIT or Fed Tax), Social Security (labeled FICA-SS or OASDI), Medicare (labeled FICA-Med or HI), state income tax, local income tax, and any voluntary deductions like health insurance premiums or retirement contributions. Some deductions reduce your taxable income (called pre-tax deductions), while others do not. Your pay stub should clearly label which is which.

Checking If Your Withholding Is Correct

The IRS provides a free Withholding Estimator on its website (irs.gov) that asks about your income, filing status, dependents, and other factors, then tells you whether you are likely to owe money or receive a refund. If the estimator shows you will owe a large amount or get a large refund, you can adjust your W-4 to change your withholding for the rest of the year.

Many paycheck calculators are also available online—search "paycheck calculator" and enter your gross pay, state, and filing status to see an estimate of your net pay. These calculators use the same IRS tables and formulas that your employer uses, so they give you a realistic picture of what to expect. Keep in mind that calculators use current-year tax rates and wage caps, so results change each January.

If you have a complex situation—multiple jobs, self-employment income, investment income, or a spouse who also works—the Withholding Estimator is more reliable than a straightforward calculator because it accounts for all your income sources.

What Happens at Tax Time

In January or February, your employer sends you a W-2 form showing your total wages for the year and the total federal, state, and local taxes withheld. You use this form to file your tax return. The IRS compares the taxes you withheld throughout the year to your actual tax bill based on your income and deductions.

If you withheld more than you owe, you receive a refund. If you withheld less, you owe the difference. The amount you owe or the refund you receive depends on your actual tax situation—your filing status, deductions, credits, and total income from all sources. Withholding is just an estimate; your tax return is the final accounting.

If you consistently owe money or get a large refund, adjust your W-4 the following year. Owing money means you should claim fewer allowances to increase withholding. Getting a large refund means you should claim more allowances to decrease withholding and take home more pay each month.

Frequently Asked Questions

Why is my withholding different from my coworker's if we earn the same amount?

Your W-4 answers are different. If you claim more dependents or allowances, less is withheld. If you are married and your spouse also works, you may need to adjust your withholding to account for both incomes. Your filing status also matters—single filers and married filers have different withholding tables.

Can I change my withholding in the middle of the year?

Yes. You can submit a new W-4 to your employer at any time. The new withholding takes effect on your next paycheck. If you got married, had a child, or your income changed significantly, updating your W-4 helps may support you do not overpay or underpay taxes for the rest of the year.

What if I do not want any federal tax withheld?

You can claim exempt status on your W-4 if you had no tax liability last year and expect none this year. However, if you claim exempt and then owe taxes, you may face penalties. This option is only safe if you genuinely expect to owe nothing.

Does my employer withhold taxes on bonuses differently?

Some employers use the aggregate method, which treats your bonus as part of your regular pay and calculates withholding using the standard tables. Others use the percentage method, which withholds a flat 22% (or 37% if the bonus is over $1 million). Either way, the withholding is an estimate; your actual tax bill is calculated when you file your return.

Why do I owe taxes if taxes were withheld from my paycheck?

Withholding is based on your W-4 answers and assumes a standard situation. If you have income your employer does not know about (self-employment, investment income, a second job), your withholding may be too low. If you claim too many allowances, withholding is also too low. Your tax return accounts for all your income and calculates what you actually owe.