How to Read Your Pay Stub, Line by Line
By the Stoia team · August 16, 2026 · 6 min read
Most people can quote their salary and the amount that lands in checking, and almost nothing about the ten lines in between. That gap is where payroll mistakes hide, and they are more common than anyone admits: a wrong withholding election, a benefit deduction that kept running after you canceled it, a 401(k) percentage that never got updated after a raise. Reading a pay stub takes about four minutes once you know what each line is doing. Here is the whole document, top to bottom.
Start at the top: gross pay
Gross pay is what you earned before anything was taken out: your salary divided by the number of pay periods, or hours times rate, plus overtime, bonuses, and commissions for that period. Every other line on the stub is subtracted from this number, so if gross is wrong, everything below it is wrong too. Check it first: on a $78,000 salary paid biweekly, gross should read $3,000 per period ($78,000 divided by 26). If you are hourly, multiply your hours by your rate and confirm the overtime line used time-and-a-half where it applied.
Federal income tax withholding
The federal income tax line is not your tax. It is an estimate, calculated from the Form W-4 you filed with your employer: your filing status, dependents, other income, and any extra amount you asked to withhold. Payroll runs those inputs through IRS tables and holds back a slice of each check. At filing time the real bill is computed, and the difference between what was withheld and what was owed becomes your refund or your balance due. A big refund means this line ran high all year; a surprise bill means it ran low. Either way, the fix lives on the W-4, not in April.
The FICA lines: Social Security and Medicare
These two lines fund Social Security and Medicare, and unlike federal withholding they are flat and predictable: 6.2% of gross for Social Security and 1.45% for Medicare, 7.65% combined. Your employer quietly pays a matching 7.65% on top that never appears on your stub. Two wrinkles: the Social Security portion stops once your wages for the year pass an annual cap (a dollar figure that changes every year), and a small extra Medicare percentage kicks in above a high-income threshold. Because these are flat rates, they are the easiest lines to verify: multiply your gross by 6.2% and 1.45% and the stub should match to the penny.
State and local lines
Depending on where you live and work, you may see a state income tax line, a city or county tax, and small state insurance items such as disability or paid family leave. A handful of states have no income tax line at all. The thing to watch here is the state itself: if you moved or started working remotely from a different state, payroll needs to know, and this line is where you catch it when they do not.
Pre-tax vs. post-tax deductions
Everything else on the stub is a deduction you (or your benefits enrollment) chose, and the order matters. Pre-tax deductions come out before taxes are calculated, which shrinks the income those taxes apply to. Post-tax deductions come out after. Same dollar, very different cost to you.
| Deduction | Usually | What it typically skips |
|---|---|---|
| Traditional 401(k) | Pre-tax | Federal and state income tax (not FICA) |
| Health, dental, vision premiums | Pre-tax | Income tax and usually FICA |
| HSA or FSA contributions | Pre-tax | Income tax and usually FICA |
| Roth 401(k) | Post-tax | Nothing now (withdrawals later) |
| Disability or life insurance add-ons | Often post-tax | Nothing |
| Garnishments, union dues | Post-tax | Nothing |
This ordering is why a $200 pre-tax contribution reduces your take-home by less than $200: part of it comes out of money that would have gone to taxes anyway. It is also why the math from gross to net is not a single subtraction. If you want to see the whole chain computed with current-year tax figures, the paycheck calculator walks gross to net with every layer visible.
Net pay and the YTD columns
Net pay is what survives: gross minus taxes minus deductions, the number that actually hits your account. Next to almost every line you will also find a year-to-date (YTD) column, the running total since January 1. The YTD columns are the audit trail: they are what your W-2 is built from in January, and they are how you catch a deduction that ran one paycheck too long or a bonus that never showed up. When something looks off on a single stub, the YTD column tells you how long it has been off.
The three numbers worth checking every January (and after every raise)
- Federal withholding per paycheck. January resets the tax tables, and a raise changes your income mid-stream. Compare the new withholding line against an estimate from the paycheck calculator and adjust your W-4 if the gap is large in either direction. Ten minutes here prevents both the April bill and the interest-free loan to the government.
- Your pre-tax elections. A 401(k) percentage set three years ago quietly ignores every raise since. Check that the contribution line reflects what you currently intend, and that benefit premiums match what you actually enrolled in this year.
- The FICA arithmetic. Multiply gross by 7.65% and confirm the two lines add up. It takes fifteen seconds, and payroll systems do occasionally misclassify a bonus or apply the Social Security cap at the wrong time.
When this gets harder
Stubs with restricted stock vesting, commission true-ups, or multi-state work carry extra lines that follow the same logic but need a closer read: vested shares appear as income at their market value, and a relocation can split state lines mid-year. The structure stays the same: gross at the top, taxes and deductions in the middle, net and YTD at the bottom.
Your pay stub explains one paycheck. Where the money goes after it lands is the other half of the story, and that is the part Stoia is built to keep visible: every account, every category, one picture that updates itself.