Understanding your paycheck
Your gross salary is almost never what lands in your bank account. Between the number on your offer letter and the deposit you actually see, several layers of tax and deductions come out first: federal income tax, FICA payroll taxes, state income tax, and any pre-tax benefits you elect. This calculator estimates your real take-home pay so you can budget around the number that matters — what you keep.
Understanding each deduction does more than satisfy curiosity. It shows you which levers you actually control. You cannot change the tax brackets, but you can change how much you contribute to a 401(k), an HSA, or other pre-tax accounts — and those choices directly change both your tax bill and your take-home pay.
How your take-home pay is calculated
The calculation runs in a specific order, because some deductions reduce the income that later taxes are applied to:
- Start with gross pay for the period (annual salary divided by the number of pay periods, or hourly wage times hours).
- Subtract pre-tax deductions — 401(k), HSA, FSA, and most health insurance premiums. This lowers your taxable income.
- Apply FICA taxes — Social Security and Medicare, calculated on most of your gross pay.
- Apply federal income tax using progressive brackets on your taxable income.
- Apply state (and any local) income tax.
- Subtract post-tax deductions such as Roth 401(k) contributions.
Whatever remains is your net pay — the amount actually deposited.
A worked example
Consider someone earning $80,000 a year, paid twice a month (24 paychecks), contributing 6% to a traditional 401(k), living in a state with a 5% flat income tax:
| Line | Annual |
| Gross salary | $80,000 |
| 401(k) contribution (6%, pre-tax) | −$4,800 |
| FICA (7.65%) | −$6,120 |
| Federal income tax (est.) | −$8,100 |
| State income tax (5%) | −$3,760 |
| Estimated take-home | $57,220 |
That works out to roughly $2,384 per paycheck. Notice that the $4,800 going into the 401(k) is not lost — it is invested for retirement and it lowered the income that federal and state tax were charged on.
FICA: the tax everyone pays
FICA is two payroll taxes combined: Social Security at 6.2% (up to an annual wage cap that adjusts each year) and Medicare at 1.45% (no cap). Together that is 7.65% deducted from most of your gross pay. High earners pay an additional 0.9% Medicare surtax on wages above $200,000. Your employer quietly matches the Social Security and base Medicare portions, so the true tax funding these programs is roughly double what you see on your stub.
Federal income tax and why your effective rate is lower
The US uses progressive tax brackets, and this is the single most misunderstood part of a paycheck. Being "in the 22% bracket" does not mean 22% of your income is taxed at 22%. Only the portion of income that falls within that bracket is taxed at that rate; income below it is taxed at the lower bracket rates. As a result, your effective tax rate — total tax divided by total income — is always lower than your top marginal bracket. This is also why earning one more dollar never reduces your total take-home pay.
The power of pre-tax savings
Pre-tax contributions are one of the few ways to legally reduce your tax bill while building wealth. A dollar you route into a traditional 401(k) or HSA is not taxed this year, so the real cost to your paycheck is less than a full dollar. In the 22% bracket, contributing $100 only reduces take-home by about $78 — the other $22 was tax you would have paid anyway. HSAs are especially powerful because qualified medical withdrawals are never taxed, making them triple tax-advantaged.
Common mistakes to avoid
- Budgeting off gross salary. Always plan around take-home; the gap can be 25%–35%.
- Ignoring the 401(k) employer match. If your employer matches contributions and you do not contribute enough to get the full match, you are leaving free money on the table.
- Forgetting pay-period math. Being paid biweekly (26 checks) versus semi-monthly (24 checks) changes each check's size even at the same salary.
- Over-withholding on purpose. A large refund feels good but means you gave the government an interest-free loan all year.
Frequently asked questions
Why is my take-home pay so much lower than my salary?
Federal income tax, FICA (7.65%), state income tax, and pre-tax deductions all come out before you are paid. Combined, these commonly reduce gross pay by 25%–35% depending on income and location.
What is the difference between marginal and effective tax rate?
Your marginal rate is the tax on your next dollar of income — your top bracket. Your effective rate is total tax divided by total income, which is always lower because progressive brackets tax lower portions of income at lower rates.
Do pre-tax deductions really save me money?
Yes. Contributions to a traditional 401(k), HSA, or FSA lower your taxable income, so you pay less income tax this year. The net cost to your paycheck is less than the amount contributed.
How does pay frequency affect each paycheck?
Your annual pay is divided by the number of pay periods. Biweekly pay (26 checks) produces slightly smaller individual checks than semi-monthly pay (24 checks) at the same salary, though the annual total is identical.
Which states have no income tax?
Several states levy no state income tax, while others exceed 10%. Enter your specific state rate for an accurate estimate. This tool uses a flat state rate for simplicity; some states use their own brackets.
Sources & references
- Internal Revenue Service — federal tax withholding and brackets · irs.gov
- Social Security Administration — FICA and payroll tax rates · ssa.gov
- Consumer Financial Protection Bureau — budgeting on take-home pay · consumerfinance.gov
Estimates are for educational purposes only and are not tax advice. Actual withholding depends on your W-4, filing status, and local rules. Consult a tax professional for your situation.