Breaking Down the Variables
Here are seven common reasons. 1. Federal income-tax withholding. Your employer withholds money toward your federal income-tax liability based on payroll rules and your Form W-4. Withholding is not the same thing as your final tax bill. 2. Social Security and Medicare. FICA taxes reduce your paycheck even when you do not owe federal income tax after filing. For 2026, employee Social Security withholding is 6.2% up to $184,500 of covered wages, while Medicare is 1.45% without a wage-base limit. 3. State or local taxes. Depending on where you live and work, state or local income taxes can take another portion of gross pay. 4. Benefits. Health, dental, vision, disability and other benefits may be deducted from your paycheck. The amount can be easy to overlook because it may have been included in your compensation discussion rather than your salary headline. 5. Retirement contributions. A 401(k) or other retirement contribution lowers current take-home pay because you are directing part of your compensation somewhere other than your checking account. 6. Pay frequency. An annual salary is not the same as one paycheck. Divide the annual amount by the number of pay periods to estimate gross pay per check before deductions. 7. Variable or unusual payroll items. Overtime, bonuses, unpaid leave, reimbursements, garnishments and payroll corrections can change a particular check.
The best way to find the reason is to compare your offer letter with your pay stub. Start with annual salary, then verify the pay period and gross earnings. From there, examine every deduction rather than focusing only on the final net-pay number.
How Deductions and Taxes Change the Outcome
If the numbers still do not make sense, use a paycheck calculator to recreate the estimate using your state, pay frequency and deductions. If the calculator and payroll disagree, don't automatically assume the calculator is right. Check the assumptions first.
The goal is not to make your paycheck equal your salary. It is to understand exactly where the difference goes.