The deductions between gross and net pay fall into three categories: federal taxes, payroll taxes, and other deductions (both voluntary and required).
Federal income tax is withheld based on your W-4 elections, filing status, and income level. The more you earn, the higher your marginal federal rate, from 10% at the lowest bracket up to 37% at the highest. Most people in the $50,000 to $100,000 range face effective federal rates in the 12 to 22% range.
FICA taxes cover Social Security (6.2% on income up to $168,600 in 2024) and Medicare (1.45% on all income, plus an additional 0.9% above $200,000). These are flat rates with no withholding elections.
State income tax varies significantly. Nine states have no broad income tax. Others range from flat rates around 3 to 5% to progressive systems that can exceed 10%.
Voluntary pre-tax deductions like traditional 401(k) contributions, employer-sponsored health insurance, HSA contributions, and FSA elections reduce your taxable income before federal and state tax is calculated. They lower your tax bill while also increasing your benefits or retirement savings.
Post-tax deductions like Roth 401(k) contributions, certain life insurance premiums, or wage garnishments come out after taxes and do not reduce your taxable income.