What Gets Taken From Your Paycheck
Payroll tax is calculated by taking a percentage of your gross pay — the amount you earn before any deductions — and sending it to federal and state governments. The calculation happens in a specific order, and different taxes use different rates. Your employer does the math and withholds the money from each paycheck, then sends it to the IRS and your state on your behalf.
The main taxes withheld are federal income tax, Social Security tax, and Medicare tax. Some states also withhold state income tax. Each one is calculated separately, using different rules and percentages. Understanding how each works helps you see why your take-home pay is lower than your gross pay.
Key Takeaways
- Social Security tax is a flat 6.2 percent of your gross pay, up to a yearly income cap that changes each year.
- Medicare tax is 1.45 percent of all your gross pay with no income cap, plus an additional 0.9 percent on earnings over a threshold amount.
- Federal income tax is calculated using your W-4 form, which tells your employer how much to withhold based on your personal situation.
- Your employer matches Social Security and Medicare taxes, meaning they pay the same amount you do, but that money does not appear on your paycheck.
- State income tax rates vary by state and are calculated after federal taxes, using similar methods.
Social Security Tax: The 6.2 Percent Calculation
Social Security tax is straightforward: your employer takes 6.2 percent of your gross pay and withholds it. This happens on every paycheck until your year-to-date earnings reach a wage base limit. That limit changes each year — in 2024 it was $168,600, meaning once you earned that much in a calendar year, no more Social Security tax was withheld for the rest of that year.
The math is simple. If you earn $2,000 in a paycheck and have not yet hit the yearly cap, your employer withholds $124 for Social Security (2,000 × 0.062 = 124). If you are self-employed, you pay both the employee and employer portions — 12.4 percent total — but you can deduct half of it on your tax return.
Medicare Tax: 1.45 Percent Plus a Possible Extra
Medicare tax has two parts. The base rate is 1.45 percent of your gross pay, with no yearly income cap. Unlike Social Security, you pay Medicare tax on every dollar you earn, no matter how much you make in a year.
The second part is an additional 0.9 percent Medicare tax on earnings above a threshold. That threshold is $200,000 for single filers and $250,000 for married couples filing jointly. Once your year-to-date pay crosses that line, your employer withholds an extra 0.9 percent on all pay above the threshold for the rest of the year. If you are self-employed or have multiple jobs, you may owe this extra tax when you file your return if your combined income crosses the threshold.
On a $2,000 paycheck, the base Medicare withholding is $29 (2,000 × 0.0145 = 29). If you are below the threshold for the additional tax, that is all you pay. If you are above it, an extra $18 is withheld (2,000 × 0.009 = 18).
Federal Income Tax: Based on Your W-4 Form
Federal income tax is not a flat percentage like Social Security and Medicare. Instead, your employer uses information from your W-4 form to calculate how much to withhold. The W-4 asks about your filing status, number of dependents, other income, and whether you have a second job. Your answers determine a withholding amount that your employer uses for every paycheck.
The IRS provides tax tables and formulas that employers use to convert your W-4 answers into a dollar amount to withhold. The calculation accounts for the fact that tax rates are progressive — you pay a higher percentage on income above certain thresholds. A single person with no dependents will have more withheld than a married person with three children earning the same gross pay.
If you change your life situation — you get married, have a child, take a second job, or expect a large refund — you can file a new W-4 to adjust your withholding. The new amount takes effect on your next paycheck.
State Income Tax: Varies by Where You Live and Work
Not all states have income tax. Nine states — Alaska, Florida, Nevada, South Dakota, Tennessee, Texas, Washington, Wyoming, and New Hampshire (on dividends and interest only) — do not withhold state income tax. If you live and work in one of these states, you skip this step entirely.
In states that do have income tax, your employer withholds a percentage based on your state W-4 form or equivalent. The rates and rules vary widely. Some states use a flat percentage; others use progressive brackets like the federal system. Some states allow you to claim dependents; others do not. Your employer uses the same method as federal withholding — they apply your state form answers to tax tables to calculate the amount.
If you work in one state but live in another, you may owe tax to both. The rules depend on which state you live in and which state you work in. Most states offer a credit to avoid double taxation, but you will need to file returns in both places.
The Order of Calculation on Your Paycheck
Your employer calculates taxes in this order: first, gross pay is determined. Then Social Security and Medicare are withheld as percentages of that gross amount. Then federal income tax is withheld based on your W-4. Then state income tax is withheld if applicable. Other deductions — health insurance premiums, retirement contributions, wage garnishments — are taken out after taxes.
This order matters because some deductions reduce your taxable income. For example, if you contribute to a traditional 401(k), that money comes out before federal and state income taxes are calculated, lowering the amount those taxes are applied to. Social Security and Medicare, however, are always calculated on your full gross pay before any deductions.
What Your Employer Pays That You Do Not See
Your employer also pays taxes on your behalf that do not appear on your paycheck. They pay 6.2 percent for Social Security and 1.45 percent for Medicare — the same rates you pay. They also pay federal and state unemployment insurance taxes. These are real costs to your employer, but they are separate from what you earn and what is withheld from your pay.
This is why the total cost of hiring you is higher than your salary. If you earn $50,000 a year, your employer is also paying roughly $3,825 in Social Security and Medicare taxes on top of your salary, plus unemployment insurance. Understanding this helps explain why your gross pay and your take-home pay are different numbers.
Frequently Asked Questions
Why is my paycheck less than I expected?
Your take-home pay is your gross pay minus all withholdings. Social Security (6.2%), Medicare (1.45%), federal income tax (varies), and state income tax (if applicable) are all calculated and removed before you see the money. If you claimed zero dependents on your W-4, more federal tax is withheld, making your paycheck smaller. You can adjust your W-4 to change this.
Can I stop paying Social Security or Medicare tax?
No. These taxes are mandatory for all employees and self-employed people. The only exception is certain religious groups that have received IRS approval to opt out. If you are a regular employee, you cannot avoid these withholdings.
What happens if my employer withholds the wrong amount?
If too much is withheld, you will receive a refund when you file your tax return. If too little is withheld, you will owe money when you file. You can adjust your W-4 at any time to change your withholding amount going forward, which helps prevent large refunds or bills at tax time.
Do bonuses get taxed differently?
Bonuses are taxed the same way as regular pay — Social Security, Medicare, federal income tax, and state income tax are all withheld. Some employers use a flat withholding rate for bonuses (often 22 or 37 percent for federal tax), but the actual amount owed is calculated when you file your return and adjusted if needed.
Why do I pay Medicare tax on all my income but Social Security only up to a cap?
Social Security has a wage base limit because Social Security benefits are capped — higher earners do not receive proportionally higher benefits. Medicare has no cap because Medicare benefits are not capped the same way. This is a policy choice made by Congress, not a calculation rule.