Paycheck Estimator

How Paycheck Deductions Work

When you look at your paycheck stub, the gap between your gross pay and what actually hits your bank account can feel jarring. That's because several mandatory and voluntary deductions get pulled out before you see a dime. Understanding what comes out and why is the first step to making smarter financial decisions.

Your gross pay is the starting point. If you're salaried, it's your annual salary divided by the number of pay periods. If you're hourly, it's your rate times your hours. From there, deductions happen in a specific order, and that order matters because pre-tax deductions reduce the income that gets taxed.

Pre-tax deductions come out first. These include things like 401(k) contributions, traditional IRA contributions, health insurance premiums, HSA contributions, and flexible spending accounts. The big advantage here is that every dollar you put toward these deductions is a dollar that doesn't get taxed. If you're in the 22% federal bracket and you contribute $500 per month to your 401(k), you're saving $110 per month in federal taxes alone.

After pre-tax deductions, you've got your taxable income. That's what the federal government, your state, and FICA all take their cut from. Federal income tax uses a progressive bracket system, meaning different portions of your income get taxed at different rates. You don't pay the top bracket rate on your entire income; you only pay it on the portion that falls within that bracket.

2025 Federal Tax Brackets Explained

The US uses a progressive tax system with seven brackets. Here's how it works for a single filer in 2025. The first $11,600 of taxable income is taxed at 10%. Income from $11,601 to $47,150 is taxed at 12%. From $47,151 to $100,525, you're at 22%. The 24% bracket covers $100,526 to $191,950. Then 32% from $191,951 to $243,725, 35% from $243,726 to $609,350, and everything above $609,350 gets hit with 37%.

A common misconception is that moving into a higher tax bracket means all your income gets taxed at that rate. That's not how it works. If you earn $50,000 as a single filer, only the amount above $47,150 gets taxed at 22%. The rest gets taxed at the lower rates. Your effective tax rate, which is your total tax divided by your total income, ends up being much lower than your marginal rate.

For married filing jointly, all the bracket thresholds roughly double. That's why some couples see a "marriage bonus" when combining incomes. Head of household filers get wider brackets than single filers, give a break to people supporting dependents on their own.

FICA Breakdown

FICA stands for the Federal Insurance Contributions Act, and it funds Social Security and Medicare. Everyone who earns wages pays FICA; there's no way around it regardless of your filing status or deductions.

Social Security tax takes 6.2% of your wages, but only up to the wage base limit of $168,600 for 2025. Once you've earned that much in a calendar year, Social Security stops coming out of your checks. If you work multiple jobs, each employer withholds independently, and you can claim any overpayment as a credit on your tax return.

Medicare takes 1.45% of all wages with no cap. High earners face an Additional Medicare Tax of 0.9% on income above $200,000 (single) or $250,000 (married filing jointly). Unlike regular Medicare tax, this additional amount is only paid by the employee, not matched by the employer.

Five Real Paycheck Examples

Example 1 - A single filer in California earning $55,000 annually, paid bi-weekly, with 6% going to a 401(k). Their gross per paycheck is $2,115.38. After the 401(k) deduction ($126.92), federal tax, California state tax (around 4.4% effective), Social Security, and Medicare, they'd take home approximately $1,532 per paycheck. That's about $39,832 per year in their pocket.

Example 2 - A married couple filing jointly in Texas earning $120,000. Texas has no state income tax, which makes a noticeable difference. With bi-weekly pay and no pre-tax deductions, their gross is $4,615.38. After federal tax and FICA, they take home about $3,582 per paycheck, or roughly $93,132 annually. The zero state tax saves them thousands compared to a high-tax state.

Example 3 - An hourly worker in New York making $22/hour, working 40 hours a week, single filer. That's $45,760 annually. After New York's relatively steep state and city taxes, federal tax, and FICA, a bi-weekly paycheck of $1,760 gross becomes around $1,282 net. The effective total tax rate comes out near 27%.

Example 4 - A high earner making $250,000 in Washington state (no income tax), married filing jointly, contributing 10% to a 401(k). Bi-weekly gross is $9,615.38. The 401(k) takes $961.54 pre-tax. Federal tax on the reduced income, FICA (including Additional Medicare Tax), and deductions leave about $6,340 per paycheck. The effective rate sits around 27.5%.

Example 5 - A head of household in Florida earning $38,000, hourly at $18.27 for 40 hours. No state tax in Florida. With the head of household standard deduction and a more favorable bracket structure, their bi-weekly take-home after federal tax and FICA is about $1,195 on a $1,461 gross. That's an effective rate of about 18%.

States Without Income Tax

Nine states don't tax wage income at all. Alaska, Florida, Nevada, New Hampshire, South Dakota, Tennessee, Texas, Washington, and Wyoming. If you're thinking about relocating and your work is remote-friendly, the difference can add up fast. Someone earning $100,000 in California might pay $5,000-6,000 in state income tax that they'd completely avoid in Texas or Florida.

But don't just look at income tax in isolation. States without income tax often make up the revenue elsewhere, typically through higher property taxes or sales taxes. Texas, for instance, has some of the highest property tax rates in the country. Washington state has a steep sales tax. It's worth running the full numbers before making a move based solely on income tax savings.

Browser Compatibility

Related Packages and Resources

For developers building payroll or tax tools, these npm packages could be helpful:

• taxee-tax-statistics - US federal and state tax rate data that's updated annually. Useful if you're building your own calculator.
• salary - A small utility for converting between different pay frequencies (annual, monthly, weekly, hourly).
• currency.js - Handles currency formatting and avoids floating-point issues that can crop up in financial calculations.

Community Discussions

• How to format numbers as currency in JavaScript - Stack Overflow
• Round to at most 2 decimal places - Stack Overflow
• Print number with commas as thousands separators - Stack Overflow
• Understanding marginal vs. effective tax rates - Hacker News
• The real cost of living in different US states - Hacker News

Frequently Asked Questions