Paycheck Calculator

How Paycheck Deductions Work

Every pay period, your employer withholds a series of mandatory and voluntary deductions from your gross earnings before depositing your net take-home pay. Understanding each deduction helps you verify your pay stub is accurate, optimize your tax situation, and plan your monthly budget with confidence. The major categories of deductions are federal income tax, state income tax, FICA taxes (Social Security and Medicare), and pre-tax benefit contributions.

Federal income tax is typically the largest single deduction for most workers. The amount withheld depends on your W-4 elections, filing status, and gross pay. Your employer uses IRS Publication 15-T to calculate withholding based on the information you provided on your Form W-4. The withholding is designed to approximate your annual tax liability so you neither owe a large amount nor receive an excessively large refund when you file your return.

State income tax withholding varies by state. Nine states — Alaska, Florida, Nevada, New Hampshire, South Dakota, Tennessee, Texas, Washington, and Wyoming — impose no state income tax. Other states range from flat rates around 3% (Indiana, Pennsylvania) to progressive systems with top brackets above 10% (California, New York, Oregon). Some localities (New York City, certain Ohio cities, Maryland counties) impose additional local income taxes that further reduce your paycheck.

FICA taxes fund Social Security and Medicare. Social Security tax is 6.2% of your gross wages up to the annual wage base of $168,600 in 2025. Once your year-to-date earnings exceed that cap, Social Security withholding stops for the remainder of the year, giving you slightly larger paychecks in the final months. Medicare tax is 1.45% of all wages with no cap, plus an additional 0.9% surtax on wages exceeding $200,000 (single) or $250,000 (married filing jointly).

Pre-tax deductions such as traditional 401(k) contributions, HSA contributions, and employer-sponsored health insurance premiums are subtracted from your gross pay before federal and state income taxes are calculated. This reduces your taxable income and current tax bill. However, most pre-tax deductions (except certain Section 125 cafeteria plan benefits) are still subject to FICA taxes.

Paycheck Calculation Steps

Your paycheck goes through a multi-step calculation process. Here is how your employer arrives at your net pay each period:

1. Start with Gross Pay. This is your base pay for the period. For a salaried employee earning $75,000 annually paid biweekly, gross pay is $75,000 / 26 = $2,884.62 per paycheck.
2. Subtract Pre-Tax Deductions. Deduct 401(k) contributions, HSA contributions, and pre-tax insurance premiums. For example, a 6% 401(k) contribution on $2,884.62 is $173.08. This brings adjusted gross to $2,711.54.
3. Calculate Federal Income Tax. Your employer annualizes the adjusted gross ($2,711.54 x 26 = $70,500), subtracts the standard deduction ($15,000 for single filers), applies the progressive bracket rates to the resulting $55,500 in taxable income, and divides the annual tax back by 26. Approximate federal withholding: $313 per paycheck.
4. Calculate State Income Tax. Similar process using your state's brackets or flat rate. For a 5% flat-rate state, approximately $136 per paycheck on the adjusted gross.
5. Calculate FICA Taxes. Social Security: $2,884.62 x 6.2% = $178.85. Medicare: $2,884.62 x 1.45% = $41.83. Total FICA: $220.68. Note that FICA is calculated on gross pay, not the amount after pre-tax deductions.
6. Subtract All Withholdings. Gross $2,884.62 minus pre-tax deductions ($173.08) minus federal tax ($313) minus state tax ($136) minus FICA ($220.68) = net pay of approximately $2,041.86.

Key Paycheck Terms

W-4 Form is the Employee's Withholding Certificate you submit to your employer. It tells your employer how much federal income tax to withhold. The 2020 redesign eliminated numbered allowances in favor of a system based on filing status, multiple jobs, dependents, other income, and additional deductions. You can update your W-4 at any time — common reasons include getting married, having a child, taking a second job, or receiving a large refund or tax bill.

Filing Status determines your standard deduction amount and tax bracket thresholds. Single filers have the narrowest brackets and smallest standard deduction ($15,000 in 2025). Married filing jointly doubles the bracket widths and standard deduction ($30,000). Head of household falls between the two and requires you to be unmarried and pay more than half the cost of maintaining a home for a qualifying dependent.

Pre-Tax vs. Post-Tax Deductions. Pre-tax deductions (traditional 401(k), HSA, FSA, employer health insurance) reduce your taxable income, lowering your current tax bill. Post-tax deductions (Roth 401(k), Roth IRA, disability insurance, union dues) are taken from your pay after taxes are calculated, so they do not reduce your current tax liability but may provide tax-free income later (in the case of Roth contributions).

FICA (Federal Insurance Contributions Act) encompasses both Social Security (officially Old-Age, Survivors, and Disability Insurance, or OASDI) at 6.2% and Medicare Hospital Insurance (HI) at 1.45%. Your employer matches both amounts, making the total FICA contribution 15.3% of your wages. Self-employed individuals pay both halves through the self-employment tax.

Additional Medicare Tax is a 0.9% surtax that applies to wages exceeding $200,000 for single filers or $250,000 for married filing jointly. Unlike regular Medicare tax, the employer does not match this surtax. It applies to all wages above the threshold regardless of other income.

Federal vs. State Deductions

The table below compares key differences between federal and state paycheck deductions:

Practical Examples

Example 1: Single Filer Earning $75,000

A single filer earning $75,000 annually, paid biweekly with a 5% state tax rate and 6% 401(k) contribution. Gross per paycheck: $2,884.62. After a $173.08 pre-tax 401(k) deduction, federal taxable income is approximately $55,500 annually. Federal withholding: roughly $313/paycheck. State tax: approximately $136. Social Security: $178.85. Medicare: $41.83. Net take-home pay: approximately $2,042 per paycheck, or about $53,092 annually. The effective total tax rate (excluding 401(k)) is about 24.5%.

Example 2: Married Filing Jointly, $120,000

A married couple where one spouse earns $120,000, paid semi-monthly (24 periods) in a 5% state tax state, with an 8% 401(k) contribution. Gross per paycheck: $5,000. Pre-tax 401(k): $400. With the $30,000 MFJ standard deduction and $9,600 annual 401(k), federal taxable income is about $80,400. Federal withholding: approximately $383/paycheck. State tax: approximately $230. Social Security: $310. Medicare: $72.50. Net take-home pay: approximately $3,605 per paycheck, or about $86,520 annually. The larger MFJ standard deduction and wider brackets provide meaningful tax savings compared to single filing.

Example 3: High Earner, $200,000

A single filer earning $200,000, paid biweekly in California (approximately 9.3% effective state rate), with a 10% 401(k) contribution (capped at $23,500 annually). Gross per paycheck: $7,692.31. Pre-tax 401(k): approximately $904. Federal taxable income is about $161,500 annually. Federal withholding: approximately $1,132/paycheck. State tax: approximately $632. Social Security: $476.92 (until hitting the $168,600 cap mid-year). Medicare: $111.54. Net take-home pay: approximately $4,436 per paycheck. At this income level, the high earner retains about 57.7% of gross pay — the combination of progressive federal brackets, California's high state rate, and FICA creates a significant gap between gross and net.

Tips to Increase Your Take-Home Pay

Maximize your 401(k) contributions. While this reduces your paycheck in the short term, every dollar contributed to a traditional 401(k) reduces your federal and state taxable income. If your employer offers a match (commonly 50% or 100% of contributions up to 3-6% of salary), contribute at least enough to capture the full match — it is essentially free money. A 4% match on $80,000 adds $3,200 to your retirement savings annually at zero cost to you.

Use an HSA if eligible. Health Savings Accounts offer a triple tax advantage: contributions are pre-tax (reducing your paycheck taxes), growth is tax-free, and qualified medical withdrawals are tax-free. The 2025 contribution limits are $4,300 for individual coverage and $8,550 for family coverage. You must be enrolled in a high-deductible health plan (HDHP) to qualify.

Utilize a Dependent Care FSA. If you have childcare expenses, a Dependent Care Flexible Spending Account lets you set aside up to $5,000 pre-tax annually for eligible care costs. This reduces your taxable income and can save you $1,000-$2,000 in taxes depending on your bracket.

Review your W-4 annually. Life changes such as marriage, having children, buying a home, or starting a side business all affect your optimal withholding. If you received a large refund (over $1,000), you are essentially giving the government an interest-free loan — adjusting your W-4 to reduce withholding puts that money in your paycheck throughout the year instead. Conversely, if you owed a large amount, increase your withholding to avoid penalties.

Consider commuter benefits. Many employers offer pre-tax transit and parking benefits (up to $325/month for each in 2025). If you commute by public transit or pay for parking, these deductions reduce your taxable income and increase your effective take-home pay.