What net salary is and why it matters

Net salary is the money that actually lands in your bank account after taxes, insurance premiums, and other deductions come out of your gross pay. Your gross pay is what your employer agrees to pay you before anything is taken out. The difference between the two is what you need to understand to know what you can actually spend.

Most people see their net pay on a paystub but do not know how it was calculated. Learning the math helps you spot errors, plan a budget, and understand what happens when you get a raise or change jobs.

Key Takeaways

  • Net salary equals gross pay minus federal income tax, Social Security tax, Medicare tax, state income tax (if your state has one), and any voluntary deductions like health insurance or retirement contributions.
  • Federal income tax is calculated using tax brackets and a W-4 form you fill out when you start a job; the more dependents you claim, the less tax is withheld.
  • Social Security tax is a flat 6.2 percent of gross pay up to a yearly cap, and Medicare tax is 1.45 percent with no cap.
  • Your paystub shows every deduction line by line, so you can verify the math yourself or spot when something changed.
  • Voluntary deductions like 401(k) contributions, health insurance premiums, and FSA deposits reduce your taxable income before federal tax is calculated.

Start with gross pay and list every deduction

To calculate net salary by hand, write down your gross pay for the pay period. Then list every deduction that will come out. Most paystubs show these in two groups: mandatory deductions (taxes) and voluntary deductions (retirement, insurance, and other benefits).

Mandatory deductions are federal income tax, Social Security tax, Medicare tax, and state income tax if your state has one. Voluntary deductions might include a 401(k) contribution, health insurance premium, dental or vision insurance, a flexible spending account (FSA), a health savings account (HSA), life insurance, or a union dues payment. Some employers also deduct wage garnishments or court-ordered child support.

The order matters: some voluntary deductions reduce your taxable income before federal tax is calculated, while others come out after. Your paystub will show the order in which they are applied.

Calculate federal income tax using your W-4

Federal income tax is the largest deduction for most people, and it is the one you control most directly. When you start a job, you fill out a W-4 form that tells your employer how much tax to withhold from each paycheck. The form asks for your filing status (single, married, head of household), the number of dependents you claim, and whether you have other income or jobs.

The more dependents you claim, the less federal tax your employer withholds. If you claim zero dependents, more tax comes out of each check. If you claim too many, you may owe money when you file your tax return in April. If you claim too few, you get a refund.

Your employer uses IRS tax tables that match your filing status, pay frequency, and W-4 claims to calculate the exact amount. You do not need to do this math yourself — your employer's payroll system does it. But you can check it using the IRS tax withholding calculator on irs.gov, which asks the same questions as the W-4 and tells you whether your withholding is roughly correct.

Add Social Security and Medicare taxes

Social Security tax is 6.2 percent of your gross pay, up to a yearly cap. In 2024, the cap is $168,600 of gross income, which means once you earn that much in a year, no more Social Security tax comes out for the rest of the year. This cap changes each year.

Medicare tax is 1.45 percent of your gross pay with no cap — it comes out of every dollar you earn, all year. If you earn more than $200,000 as a single filer (or $250,000 if married filing jointly), an additional 0.9 percent Medicare tax comes out on the income above that threshold.

Both are calculated on your gross pay before voluntary deductions. So if you earn $2,000 gross in a pay period, Social Security tax is $124 and Medicare tax is $29, regardless of how much you contribute to your 401(k).

Account for state and local income taxes

Not all states have an income tax. Nine states — Alaska, Florida, Nevada, South Dakota, Tennessee, Texas, Washington, Wyoming, and New Hampshire (on dividends and interest only) — do not tax wages. If you live and work in one of these states, you skip this step.

If your state does tax income, the rate and calculation method vary. Some states use a flat percentage; others use tax brackets like the federal system. Your employer withholds state income tax based on a state W-4 form you fill out, similar to the federal one. A few cities, including New York City and Columbus, Ohio, also tax wages, and your employer will withhold that too.

You can find your state's tax rate and withholding rules on your state revenue or taxation department website. The paystub your employer gives you will show the state tax withheld.

Subtract voluntary deductions in the right order

Voluntary deductions come out in a specific order because some reduce your taxable income before federal tax is calculated, while others do not. Deductions that reduce taxable income are called pre-tax deductions. These include health insurance premiums, dental and vision insurance, FSA contributions, HSA contributions, and 401(k) contributions.

If you contribute $300 per pay period to your 401(k), your taxable income is reduced by $300 before federal income tax is calculated. So instead of paying federal tax on $2,000 gross, you pay it on $1,700. This saves you money on federal tax.

Deductions that do not reduce taxable income are called post-tax deductions. These include Roth 401(k) contributions, some life insurance premiums, and wage garnishments. These come out after federal tax is calculated, so they do not lower your federal tax bill.

Your paystub shows the order: pre-tax deductions are subtracted first, then federal tax is calculated on the remaining amount, then post-tax deductions come out. If you are unsure which deductions are pre-tax at your job, ask your payroll or benefits department.

Put the calculation together

Here is a worked example. Suppose you earn $2,000 gross per pay period, you are single with no dependents, you live in a state with a 5 percent income tax, and you contribute $200 per pay period to your 401(k) and $150 to health insurance.

Start with gross: $2,000. Subtract pre-tax deductions: $200 (401k) + $150 (health insurance) = $350. Taxable income is now $1,650. Federal income tax on $1,650 (using 2024 tax tables for a single filer paid biweekly) is roughly $180. Social Security tax is $2,000 × 0.062 = $124. Medicare tax is $2,000 × 0.0145 = $29. State income tax is $1,650 × 0.05 = $82.50.

Total deductions: $350 (pre-tax) + $180 (federal) + $124 (Social Security) + $29 (Medicare) + $82.50 (state) = $765.50. Net salary is $2,000 − $765.50 = $1,234.50.

Your actual paystub will show each line separately so you can verify the math. If a number looks wrong, compare it to the previous pay period or ask your payroll department to explain it.

Frequently Asked Questions

Why does my net pay change from one paycheck to the next if my salary is the same?

Federal income tax withholding can shift slightly based on the number of pay periods in a month or year, and some deductions like health insurance premiums may change. If you get paid biweekly, some months have three paychecks instead of two, which can affect your net pay. Bonus checks and overtime are also taxed differently than regular pay.

What does it mean if I claim zero dependents on my W-4?

Claiming zero dependents tells your employer to withhold the maximum federal income tax from each paycheck. This usually results in a refund when you file your tax return in April, because you overpaid during the year. Claiming the correct number of dependents results in a smaller refund or no refund at all.

Can I reduce my net salary deductions by changing my W-4?

Changing your W-4 changes how much federal income tax is withheld, but it does not change your total tax bill for the year — it only changes when you pay it. Claiming more dependents reduces the tax withheld from each check, so your net pay goes up, but you may owe money in April. Claiming fewer dependents increases the tax withheld, so your net pay goes down, but you get a refund.

Do pre-tax deductions like 401(k) contributions reduce my Social Security and Medicare taxes?

No. Social Security and Medicare taxes are calculated on your full gross pay, not on your taxable income after pre-tax deductions. Only federal income tax and state income tax are reduced by pre-tax deductions like 401(k) and health insurance contributions.

How do I know if my paystub is correct?

Check that your gross pay matches your salary or hourly rate times hours worked. Verify that federal, Social Security, Medicare, and state taxes match the rates and calculations shown above. Make sure your voluntary deductions match what you signed up for. If anything looks wrong, ask your payroll department for an explanation before the next pay period.