A salary of 80,000 dollars a year does not mean 80,000 dollars of take-home pay, and the gap is not one mystery deduction. It is several smaller deductions, taken in a particular order, and one of them behaves differently from the rest. Reading the stub in that order is what makes the gap add up.
Enter the same salary and deductions in the calculator, then compare its federal and FICA lines with the stub below.
One stub, from gross to net
Take a single filer paid biweekly, earning 80,000 dollars a year, with a health premium of 1,800 dollars a year and a 401k contribution of 4,000 dollars a year. Gross pay per paycheck is 80,000 divided by 26, which is 3,076.92 dollars. The annual figures below are the ones to check, because per-paycheck figures carry rounding of a cent or two.
| Line | Annual amount |
|---|---|
| Gross salary | $80,000 |
| Health premium, pre-tax | -$1,800 |
| 401k contribution | -$4,000 |
| Federal income tax | -$7,494 |
| Social Security, 6.2 percent | -$4,848.40 |
| Medicare, 1.45 percent | -$1,133.90 |
| Net pay | $60,723.70 |
Net pay per paycheck is 60,723.70 divided by 26, which is 2,335.53 dollars. The gap between gross and net per paycheck is therefore about 741 dollars, spread across five lines, not taken by one tax.
The order matters, and the 401k is the trap
The health premium reduces both federal taxable income and FICA wages, because it is paid through a pre-tax plan. Wages after the health premium are 78,200 dollars. The 401k contribution then reduces federal taxable income further, to 58,100 dollars after the 16,100 dollar single standard deduction for 2026. Federal tax on 58,100 dollars is 10 percent of the first 12,400 dollars, which is 1,240 dollars, plus 12 percent of the slice from 12,400 to 50,400 dollars, which is 4,560 dollars, plus 22 percent of the slice from 50,400 to 58,100 dollars, which is 1,694 dollars. The total is 7,494 dollars.
Here is the point most readers miss: a 401k contribution does not reduce Social Security or Medicare wages. Social Security is therefore 6.2 percent of 78,200 dollars, which is 4,848.40 dollars, and Medicare is 1.45 percent of 78,200 dollars, which is 1,133.90 dollars. If you subtracted the 401k before FICA as well, you would understate both lines by about 248 dollars and 58 dollars a year, and your net pay would look higher than it is. This guide gives general information only, not a determination for an individual return.
What is not a tax at all
Two lines on the stub are not taxes, even though they reduce take-home pay in the same way. The health premium buys coverage, and the 401k contribution is your own retirement saving, not money kept by an employer or a tax authority. Treating them as taxes overstates the tax burden and understates what you actually received for the money. In this example, taxes alone are federal tax 7,494 dollars plus Social Security 4,848.40 dollars plus Medicare 1,133.90 dollars, which is 13,476.30 dollars. The remaining 5,800 dollars of the gap is the health premium and the 401k contribution.
State tax, local tax, and any after-tax deduction, such as a Roth 401k contribution or a union due, would widen the gap further, and none of them is in the national calculator result. A state paycheck page adds the state line for that state.
Check your own stub in this order
Start with gross pay and pay frequency, then list pre-tax deductions, then federal tax, then Social Security, then Medicare, then state and local lines, then after-tax deductions. If a line does not fit that order, ask which base it was calculated on: federal taxable income, FICA wages, or gross pay. Most stub confusion comes from assuming every line used the same base, when they did not. For the federal slice on its own, see the bracket guide and the standard deduction guide, and for the FICA slice, see the FICA guide linked from the paycheck hub.
FAQs
Why is my first paycheck of the year different from a later one?
It can differ if a deduction starts or stops, if pay frequency changes, or if Social Security stops late in the year once the wage base is reached. Federal and Medicare rates do not change mid-year on their own.
Does a raise raise my net pay by the full raise?
No. A raise is taxed at the marginal rate on the extra slice, and Social Security and Medicare apply to the extra wages as well, until any wage base is reached. Net pay rises, but by less than the gross raise.
Is net pay the same as taxable income?
No. Taxable income is the base federal tax is calculated on, after deductions. Net pay is what remains after all deductions, including FICA and any state tax, are taken out.