Most people look at one number on a pay stub. The rest of it is where errors hide, and payroll errors are more common than you would like.
This guide covers what each line means and how to check it.
Gross pay
The top figure is what you earned before anything came out.
For a salaried employee it is your annual salary divided by the number of pay periods: 26 for biweekly, 24 for semi-monthly, 12 for monthly. The two middle options are not the same thing, and the difference catches people out:
- Biweekly is every two weeks: 26 cheques, and two months a year contain three of them.
- Semi-monthly is twice a month: 24 cheques, always on fixed dates, each one slightly larger.
For hourly work, gross is hours × rate, plus overtime at 1.5× for hours over 40 in a week under federal law.
To check: annual salary ÷ pay periods should match. If your salary changed mid-period, expect a prorated figure.
Pre-tax deductions
These come out before tax is calculated, which is what makes them valuable. Each dollar reduces your taxable income, saving you tax at your marginal rate.
Common ones:
- 401(k) or 403(b) traditional contributions. They reduce federal and state taxable income but not Social Security and Medicare wages, so you pay FICA on them regardless.
- Health insurance premiums, usually under a Section 125 plan. These typically reduce FICA wages too, making them the most tax-efficient deduction on the stub.
- HSA contributions, likewise, when made through payroll.
- FSA contributions for healthcare or dependent care.
- Commuter benefits for transit and parking.
Roth 401(k) contributions are not pre-tax. They come out after tax and do not reduce your taxable income at all. If you see a 401(k) line that isn’t lowering your taxable wages, that is why.
Taxable wages
Gross minus pre-tax deductions. Everything downstream is calculated on this figure, and it is usually lower than your gross, which is the point.
You may see two different taxable wage figures on the same stub: one for federal income tax and one for Social Security and Medicare. They differ because 401(k) contributions reduce the first but not the second. That is correct and not an error.
FICA: Social Security and Medicare
These are fixed rates and the easiest lines to verify.
| Line | Rate | Notes |
|---|---|---|
| Social Security | 6.2% | Only on wages up to $184,500 (2026) |
| Medicare | 1.45% | No cap |
| Additional Medicare | 0.9% | On wages above $200,000 |
Your employer pays a matching 6.2% and 1.45%, which does not appear on your stub and is not deducted from you.
To check: multiply your FICA taxable wages by 0.062 and 0.0145. The results should match to the cent. If they don’t, something is wrong.
For high earners, Social Security stops once year-to-date wages pass the wage base. Your take-home rises for the rest of the year. That is expected and not an error.
Federal income tax withholding
This is the hardest line to verify, because it isn’t a simple percentage. Your employer calculates it from the W-4 you filed, using IRS tables that annualise your current pay and work out what a year of it would owe.
That is why withholding changes when your pay changes, and why a big one-off cheque can be withheld at a surprisingly high rate. The system briefly believes you earn that much every period.
To check: it should be roughly your expected annual tax divided by pay periods. A tool like the paycheck calculator gives you a reasonable expectation to compare against. Being somewhat off is normal. Being wildly off means your W-4 probably needs attention.
State and local tax
This depends entirely on where you live and work.
- Nine states levy no income tax on wages: Alaska, Florida, Nevada, New Hampshire, South Dakota, Tennessee, Texas, Washington and Wyoming.
- Some states apply a single flat rate.
- Others use graduated brackets like the federal system.
Local taxes are the ones people forget. New York City, Philadelphia, and many municipalities in Ohio and Pennsylvania levy their own income tax on top. If you live in one, expect a line for it.
Many stubs also show SDI or SUI (state disability or unemployment insurance) in states such as California, New Jersey, New York, Rhode Island and Washington.
Post-tax deductions
These come out after tax, so they do not reduce your taxable income:
- Roth 401(k) contributions
- Life and disability insurance above the employer-provided minimum
- Union dues
- Wage garnishments
- Loan repayments to your employer
- Charitable giving through payroll
Net pay
What actually reaches your bank: gross, minus pre-tax deductions, minus taxes, minus post-tax deductions.
Year-to-date columns
These are the most useful part of the stub and the most ignored. Every line has a YTD figure, and those are what you should check, not the current period.
Use them to:
- Track 401(k) progress against the annual limit.
- See when Social Security will stop, if you are a high earner.
- Sanity-check your annual tax position: multiply YTD withholding by the fraction of the year remaining and compare it to your expected liability.
- Verify your W-2 in January. The YTD figures on your final stub should match it. If they don’t, ask before you file.
What actually goes wrong
Payroll errors are more common than people assume, and nobody checks for you.
- A wrong state. This happens when you move, or work remotely across a state line, and payroll isn’t updated. It produces a genuine mess at filing time.
- A stale W-4 after marriage, divorce or a child, producing a large refund or a large bill.
- Benefit deductions that did not stop after you dropped a plan.
- Overtime at the wrong rate, or not paid at all on hours over 40.
- A missed raise, especially one effective mid-period.
- Duplicate deductions after a benefits change.
Read your first stub after any change line by line: a raise, a move, a benefits election, a life event. That is where errors appear, and the sooner they are caught the easier they are to fix.
The checklist
- Gross matches salary ÷ pay periods.
- Social Security is exactly 6.2% of FICA wages (until the wage base).
- Medicare is exactly 1.45% of FICA wages.
- Pre-tax deductions are the ones you elected, at the amounts you chose.
- State is the state you actually live and work in.
- YTD 401(k) is on pace for what you intended.
- Net pay matches what hit your account.
Compare against the paycheck calculator, which shows the same breakdown for your state and filing status. What it does and does not model is set out on the methodology page.