Your salary offer says $80,000. Your first paycheck feels much smaller. This guide explains every line on that paycheck — federal withholding, Social Security, Medicare, state tax, and pre-tax benefit deductions — so you know exactly where your money goes and how to get more of it home.
The Anatomy of a US Paycheck
- Gross Pay: Your salary or hourly pay before anything is removed.
- Federal Income Tax Withholding: Based on your W-4 form and the IRS withholding tables. Adjusting your W-4 changes this amount.
- Social Security Tax: 6.2% of wages up to $176,100 (2025). Stops at the cap — a meaningful benefit for high earners.
- Medicare Tax: 1.45% with no cap. Plus 0.9% on wages over $200,000 (single).
- State Income Tax: Varies by state. Zero in Florida, Texas, etc. Up to 13.3% in California.
- Pre-Tax Deductions: 401(k), HSA, FSA, medical/dental premiums — these reduce taxable income before federal and state tax is calculated.
- Post-Tax Deductions: Roth 401(k), some life insurance, garnishments — deducted after tax.
Pre-Tax Benefits: The Biggest Lever
Contributing to pre-tax accounts reduces your taxable income before federal and most state taxes are calculated:
- 401(k): Max $23,500 in 2025 ($31,000 if age 50+). Reduces federal and most state taxable income. No FICA savings.
- HSA (Health Savings Account): $4,300 single / $8,550 family (2025). Reduces federal income tax AND FICA — one of the most tax-efficient accounts available.
- FSA (Flexible Spending Account): Up to $3,300. Use-it-or-lose-it but reduces FICA too.
- Employer health insurance premium (employee share): Usually pre-tax, reducing FICA and income tax.
Example 1 — $60,000 Salary, Single, No State Income Tax
| Gross Salary | $60,000 |
| 401(k) contribution (6%) | −$3,600 |
| Federal Taxable Income | $56,400 |
| Standard Deduction | −$15,750 |
| Federal Income Tax (~10/12/22%) | −$5,720 |
| Social Security (6.2%) | −$3,720 |
| Medicare (1.45%) | −$870 |
| State Tax (Florida: $0) | $0 |
| Annual Take-Home | ~$46,090 |
| Monthly | ~$3,841/mo |
Example 2 — $100,000 Salary, Single, California
| Gross | $100,000 |
| Federal Tax (~$14,070) | −$14,070 |
| Social Security (6.2%) | −$6,200 |
| Medicare (1.45%) | −$1,450 |
| CA State Tax (~9.3% bracket, effective ~6.5%) | −$6,500 |
| CA SDI (0.9%) | −$900 |
| Annual Take-Home | ~$70,880 |
| Monthly | ~$5,907/mo |
The same $100K salary in Texas (no state income tax) takes home ~$77,380/yr — a $6,500 difference.
How to Increase Your Take-Home Pay
- Max your HSA first: It's the only account that avoids federal income tax, FICA, AND grows tax-free for medical expenses. A triple tax benefit.
- Adjust your W-4: If you got a large refund last year, you're loaning the government money interest-free. Adjusting your W-4 gives you more per paycheck.
- Consider living in a no-income-tax state: If your employer allows remote work, Texas vs California is a $6,500–$20,000+/yr difference on a $100K–$300K salary.
- Defer income: 401(k) contributions reduce current-year taxable income. If you're in the 22% bracket, every $1,000 contributed saves $220 in federal tax.
Calculate your US take-home pay
Open Take-Home Calculator →Why is my federal withholding different from my actual tax?
Your employer estimates your annual tax and withholds accordingly based on your W-4. When you file your return, you reconcile — if they withheld too much, you get a refund. Too little, you owe. A W-4 with the right number of allowances / additional withholding settings minimises the difference.
Does my 401(k) contribution reduce FICA taxes?
Traditional 401(k) contributions reduce federal and state income tax, but NOT FICA (Social Security + Medicare). HSA contributions made via payroll deduction do reduce FICA. This is why maxing your HSA before your 401(k) is generally recommended if you're eligible.
Source: IRS Publication 15-T, 2025. State rates approximate. Not tax advice.
Official sources
Every rate and threshold in this guide is checked against the official government sources below. Always confirm figures for your own situation before filing.