Payroll Deduction Calculator
Find your net take-home pay by subtracting federal and state income taxes, FICA (7.65%), 401(k) contributions, health insurance premiums, and other deductions from your gross paycheck. Use it each pay period to budget accurately.
About this calculator
Your gross pay is the amount you earn before any deductions; net pay (take-home pay) is what actually hits your bank account. The calculation subtracts four main categories: (1) income taxes — federal and state rates applied as percentages of gross pay; (2) FICA — a fixed 7.65% covering Social Security (6.2%) and Medicare (1.45%); (3) pre-tax retirement contributions — your 401(k) percentage reduces taxable income in practice, though this calculator applies it to gross for simplicity; and (4) fixed-dollar deductions such as health insurance premiums and other items. The formula is: Net Pay = grossPay − (grossPay × (federalTax + stateTax) / 100) − (grossPay × 7.65 / 100) − (grossPay × retirement401k / 100) − healthInsurance − otherDeductions. Adjusting any variable reveals exactly how much each deduction costs you per pay period.
How to use
Say your gross pay is $4,000, federal tax rate is 22%, state tax is 5%, 401(k) contribution is 6%, health insurance is $150, and other deductions are $50. Income taxes: $4,000 × (22 + 5) / 100 = $1,080. FICA: $4,000 × 0.0765 = $306. 401(k): $4,000 × 0.06 = $240. Fixed deductions: $150 + $50 = $200. Net pay = $4,000 − $1,080 − $306 − $240 − $200 = $2,174. Your take-home is roughly 54% of gross pay in this scenario.
Frequently asked questions
What is the difference between pre-tax and post-tax deductions on a paycheck?
Pre-tax deductions — such as traditional 401(k) contributions, health insurance premiums, and FSA contributions — are subtracted from gross pay before income taxes are calculated, reducing your taxable income. Post-tax deductions, like Roth 401(k) contributions or wage garnishments, come out after taxes have already been applied. This calculator treats 401(k) as a straight percentage deduction for simplicity; in practice, a 6% pre-tax 401(k) contribution also lowers your federal and state income tax bill, so your actual net pay would be slightly higher than shown.
How does a 401k contribution affect my net take-home pay each paycheck?
A traditional 401(k) contribution reduces your current taxable income, which means you pay less in federal and state income taxes right now — partially offsetting the contribution's impact on your paycheck. For example, contributing $240 (6% of $4,000) at a 22% federal rate saves roughly $53 in federal taxes, so your actual take-home reduction is closer to $187, not the full $240. Over a career, the tax-deferred compounding makes 401(k) contributions one of the highest-return financial moves available to employees.
Why does FICA show as a fixed 7.65% regardless of my tax bracket?
FICA taxes — Social Security at 6.2% and Medicare at 1.45% — are flat-rate payroll taxes that apply to earned income regardless of your marginal income tax bracket. Unlike federal income tax, which increases as income rises, FICA is the same percentage for a $25,000 earner as for a $100,000 earner (up to the Social Security wage base of $168,600 in 2024, after which the 6.2% portion stops). The 1.45% Medicare tax has no wage cap, and high earners pay an additional 0.9% surtax. This flat structure makes FICA predictable and easy to calculate per paycheck.