The single biggest reason your take-home pay is smaller than your salary is the stack of taxes withheld from every paycheck. Some are flat and predictable, while income tax withholding depends on your earnings and your W-4. Knowing how each works lets you estimate your net pay and understand which taxes you can influence.
FICA: Social Security and Medicare
FICA taxes are flat and come out of nearly every paycheck. Social Security is 6.2 percent of your wages up to an annual cap that the government raises most years, and it was $176,100 in 2025. Medicare is 1.45 percent on all wages with no cap, and an extra 0.9 percent applies to wages above $200,000. Combined, most workers pay 7.65 percent in FICA, and your employer quietly pays a matching amount you never see.
Federal income tax withholding
Federal income tax is withheld based on your W-4 and the progressive tax brackets, so it is not a single flat rate. Only the income that falls within each bracket is taxed at that bracket's rate, which keeps your effective rate well below your top marginal rate. Withholding is an estimate of your annual liability spread across paychecks, then reconciled when you file. Adjusting your W-4 changes how much is held back, but not the total tax you ultimately owe.
State and local taxes
Most states levy their own income tax, and a handful of cities and counties add local taxes on top. Rates range widely, from states with no income tax at all to others with progressive brackets exceeding 10 percent at the top. This is why two people with identical salaries can take home noticeably different amounts depending on where they live and work. Some states use a flat rate while others mirror the federal bracket structure.
How pre-tax benefits lower the bill
Pre-tax deductions reduce the wages that certain taxes apply to, which lowers your withholding. Traditional 401(k) contributions cut your taxable income for federal and usually state tax, though Social Security and Medicare still apply to them. Health premiums and HSA contributions made through payroll can reduce all of these taxes, including FICA. Directing money into these accounts is one of the few legal ways to increase your net-of-tax value from the same salary.
Priya earns $70,000 and contributes $4,000 to a traditional 401(k), lowering her federally taxable wages to $66,000. She still pays 7.65 percent FICA on the full $70,000, about $5,355, because retirement contributions do not escape Social Security and Medicare. Federal, state, and FICA withholding together leave her taking home roughly 75 percent of her gross.
Key takeaways
- FICA is a flat 7.65 percent for most workers: 6.2 percent Social Security up to a cap plus 1.45 percent Medicare.
- Federal income tax is progressive, so only income in each bracket is taxed at that rate.
- State and local taxes vary enormously and can swing take-home pay between locations.
- Pre-tax 401(k), HSA, and insurance premiums shrink the wages subject to tax.
Common mistakes
- Believing a raise into a higher bracket taxes your entire income at the new rate.
- Assuming 401(k) contributions avoid Social Security and Medicare taxes, which they do not.
- Overlooking that moving to a no-income-tax state can meaningfully raise take-home pay.
FAQ
Does everyone pay the same FICA rate?
Most workers pay 7.65 percent, but Social Security stops at the annual wage cap and high earners pay an extra 0.9 percent Medicare surtax above $200,000.
Can I reduce my payroll taxes?
You cannot reduce FICA much, but pre-tax retirement and health contributions lower your income-tax withholding, and HSA and premium contributions can also lower FICA.