Gross Pay vs Net Pay: The Difference Explained
Gross pay is what they earned. Net pay is what they take home. Every deduction in between, worked examples, and the third number employers forget.
Gross Pay vs Net Pay
What each one means, every deduction that sits between them, and the third number that never appears on a pay stub but leaves your bank account anyway
You offered someone $60,000. They accepted, they started, and two weeks later they are standing in your doorway holding a pay stub asking why they were paid $1,752 when the math they did in their head said $2,307.
Nothing is wrong. This is how payroll works, and the conversation happens at every business the first time someone is hired. But it is a conversation you can have before the pay stub rather than after it, and doing so requires you to actually understand the gap yourself, which is what this page is for.
Here is what most explanations of this topic leave out, and it is the reason I wrote a long one. There is not one gap. There are two. There is the gap between what the employee earned and what they received. And there is a second gap, invisible on the pay stub entirely, between what the employee earned and what you paid. Almost nobody explains the second one, and it is the one that determines whether you can afford the hire. I build FirstHR, which is where employee records live. One caveat: this is tax territory, figures change annually, and I am not a tax professional.
The Difference
Gross pay is the total an employee earned before anything is taken out. Net pay is what actually reaches their bank account after every deduction. Gross minus deductions equals net.
That is genuinely the whole concept, and if you only read one section, this is the one. Everything else on this page is an unpacking of the middle box, which is where all the complexity lives and where every question anyone has ever had about this actually comes from.
| Gross pay | Net pay | |
|---|---|---|
| What it is | Total earnings before deductions | What lands in the bank account |
| Also called | Gross wages, gross income | Take-home pay, net wages |
| Where it appears | The offer letter. Top of the pay stub | Bottom of the pay stub. Their bank statement |
| What it includes | Wages, salary, overtime, bonuses, commissions, tips | Gross minus every tax and every deduction |
| Which number is bigger | This one, always | Typically 70 to 80 percent of gross |
| Which one they can spend | None of it | All of it |
The final row is the one that explains most employee frustration. Everything discussed in a salary negotiation is gross. Everything experienced in a bank account is net. Those are different numbers and the employee is generally thinking about the first while living on the second.
What Gross Pay Is
Gross pay is everything the employee earned in the period. Everything. It is broader than people assume, and the breadth matters because every tax is calculated on the total.
Gross pay per period depends on your pay schedule: divide the annual salary by 26 for biweekly, 24 for semimonthly, 52 for weekly, or 12 for monthly. Divide by the wrong figure and every downstream number is wrong too.
The forms that drive all of this are the Form W-4, which determines federal withholding, and the Form W-2, which reports the year's totals back to the employee each January.
Two things employers get wrong here. First, overtime is fully part of gross pay and every tax applies to it. There is no reduced rate for overtime earnings, despite a persistent employee belief that overtime is somehow taxed more punitively. It is taxed identically; it simply pushes the period's total higher, which can nudge the withholding calculation.
Second, bonuses are in gross pay too. They are withheld differently, since the IRS treats them as supplemental wages and permits a flat 22 percent federal withholding when paid separately, but that is a difference in withholding method, not a different tax. The wider category is covered in supplemental pay.
What Net Pay Is
Net pay is what is left. It is an output rather than an input, and that distinction is more useful than it sounds.
If gross pay was calculated on the wrong rate, the correction is retro pay, and it has its own arithmetic and its own tax treatment.
The output-not-input point matters practically. You cannot simply decide to pay someone $2,000 net. You can decide to pay them a gross amount, and net follows from the arithmetic. If you genuinely need to guarantee a net figure, that is grossing up, it is a distinct exercise, and it is covered further down.
Everything In Between
This is the section the competition treats as a bulleted list, and it deserves better, because the details in this table are where employers actually make errors. The authoritative source for all of it is IRS Publication 15, the Employer's Tax Guide.
| Deduction | Mandatory? | Pre-tax or post-tax? | What it actually reduces | Employer match? |
|---|---|---|---|---|
| Federal income tax | Yes | n/a | Withheld per the W-4 and IRS tables. Not a flat rate | No |
| Social Security | Yes | n/a | 6.2% up to the annual wage base of $184,500 for 2026 | Yes, 6.2% |
| Medicare | Yes | n/a | 1.45% on all wages. No cap at any income | Yes, 1.45% |
| Additional Medicare | Yes | n/a | 0.9% on wages over $200,000. You must withhold it | No. Not matched |
| State income tax | Yes, in 41 states | n/a | Varies by state. Nine states levy none on wages | No |
| Local income tax | In some cities | n/a | A handful of cities levy their own. Easy to miss | No |
| Traditional 401(k) | No | Pre-tax | Federal and state income tax. NOT Social Security or Medicare | Match is your choice |
| Health premium, Section 125 | No | Pre-tax | Income tax AND FICA. The most tax-efficient deduction available | Your share is separate |
| HSA or FSA | No | Pre-tax | Income tax and generally FICA, under a cafeteria plan | Optional |
| Roth 401(k) | No | Post-tax | Nothing. Taxed now, tax-free later | Match is your choice |
| Garnishment | Yes, if ordered | Post-tax | Nothing. Calculated on disposable earnings | No |
| Union dues | Per agreement | Post-tax | Nothing | No |
Non-cash compensation follows different rules again, and some of it is taxable wages even though no money changed hands. That is the territory of fringe benefits, and it shows up in gross pay at year end whether you planned for it or not.
The Section 125 point is worth dwelling on because it is a rare case where the tax code is generous to both sides. A health premium taken pre-tax through a proper cafeteria plan lowers the employee's taxable wages and lowers your employer FICA, because you are matching on a smaller number. It costs you less than its face value, which is not true of almost anything else you offer.
Worked Example: Salaried
Abstractions are hard to hold. Here is $60,000 a year, biweekly, all the way through.
Federal income tax withholding comes from the tables in IRS Publication 15-T, and it is a lookup rather than a percentage. There is no flat federal rate on wages, which is why two employees on identical salaries can have different withholding.
Notice the amber row, because it is the thing this article exists to say. The base for income tax is $2,072.31, but the base for Social Security and Medicare is $2,187.69, because the 401(k) reduced one and not the other. Two different bases in the same calculation. That is not a technicality; it is the correct treatment, and doing it by hand in a spreadsheet is exactly where small businesses introduce errors that persist for months.
The headline: they earned $2,307.69 and received $1,752.91. That is 76 percent of gross. A quarter of their pay went somewhere else, and every cent of it went to a government or into a benefit they elected.
Worked Example: Hourly
Same logic, different starting point, and the overtime is the part worth watching.
Overtime is calculated at one and a half times the regular rate, and for a non-exempt employee the regular rate is not necessarily the hourly wage: if they earned a nondiscretionary bonus or a shift differential that week, the regular rate is higher and so is the overtime. That mechanic is covered properly in the payroll guide, and only non-exempt employees are owed overtime at all.
The hours themselves come from your timesheets, and the accuracy of the entire calculation is capped by the accuracy of that input. A wrong hour count produces a wrong gross, which produces a wrong everything.
Note that net came out at 80 percent here rather than 76 percent, purely because there were no pre-tax deductions in the example. The ratio is not a constant. It is a consequence of the employee's own elections and their state, which is why any rule of thumb about take-home percentage is close to useless for an individual.
The Third Number
Here is the section almost no competing page has, and it is the one that matters most to you. Everything above concerns the employee's two numbers. There is a third, and it is yours.
So: the employee sees $2,307.69. The employee receives $1,752.91. You pay $2,512.02. Three numbers, all different, and only two of them appear on the pay stub.
Annualize the employer share and it is roughly $5,300 on top of a $60,000 salary, before you have offered health insurance, a retirement match, or a single day of paid leave. That is the number that belongs in your hiring model, and its absence is why businesses routinely make offers they cannot actually sustain.
The full statutory picture is in statutory benefits, and the wider arithmetic of what an employee costs once voluntary benefits are added is in how much benefits cost per employee.
When the Cap Is Reached
Something happens in the autumn at every business with a well-paid employee, and almost nobody explains it in advance: their paycheck suddenly gets bigger, and nothing is wrong.
Social Security has a wage base. Medicare does not. Once an employee's year-to-date wages cross $184,500 in 2026, you stop withholding Social Security for the rest of the calendar year, and their net pay rises by 6.2 percent of gross.
The other direction of this is the Additional Medicare Tax, and it works the opposite way. Once an employee's wages with you exceed $200,000 in a calendar year, you must begin withholding an extra 0.9 percent on the excess, and continue for the rest of the year. Two things about it catch employers out.
First, you withhold it regardless of the employee's filing status. The $200,000 trigger is based on wages from you, full stop, even though the employee's actual liability depends on their household situation and gets reconciled on their return. Second, and this is the one people miss: there is no employer match on it. You match the 6.2 percent and the 1.45 percent. You do not match the 0.9 percent. It comes entirely out of the employee.
The practical instruction is to tell the employee before it happens, in both directions. An autumn paycheck that grows unexpectedly and a January paycheck that shrinks back are both alarming if nobody has explained the wage base, and both are entirely normal.
Contractors Have No Net Pay
Worth stating explicitly, because it is the cleanest illustration of what gross and net actually mean. An independent contractor has only one number.
| Employee | Contractor | |
|---|---|---|
| Gross pay | Yes. Everything they earned | The invoice amount. That is the whole number |
| Income tax withheld | Yes, per the W-4 | No. Nothing withheld |
| Social Security and Medicare withheld | Yes, 6.2% and 1.45% | No. They pay self-employment tax themselves |
| Employer FICA match | Yes. You pay 7.65% on top | No. You pay nothing on top |
| Unemployment tax | Yes. You pay it | No |
| Net pay | Yes. Typically 70 to 80% of gross | There is no net pay. They receive the gross |
| Year-end form | Form W-2 | Form 1099-NEC, if you paid $600 or more |
Read the last two rows together. A contractor receives the entire invoiced amount, and it costs you exactly that and nothing more. That looks like a discount on employing someone, and it is the reason misclassification is tempting. It is not a discount. It is a classification, determined by the actual working relationship rather than by what you decide to call it, and getting it wrong produces back taxes and penalties. The test is in employee versus contractor.
The useful framing for this article: gross and net exist because of withholding, and withholding exists because of employment. No employment, no withholding, no net pay. One number.
Terms People Confuse
Several adjacent words get used interchangeably and are not the same thing. Worth separating once, because the confusion produces real errors in offer conversations.
| Term | What it actually means | Common confusion |
|---|---|---|
| Gross pay | Total earned in a pay period, before deductions | Confused with gross income, which is broader |
| Gross income | All income from every source, including wages, investments, and side work | Not a payroll term at all. Belongs to a tax return, not a pay stub |
| Base salary | The fixed annual amount, excluding bonus and overtime | Assumed to equal gross pay. It does not, if the employee earns anything variable |
| Wages | Usually implies hourly pay, but legally covers all compensation | Used loosely. In statute, wages means everything you pay for work |
| Net pay | What lands in the bank after all deductions | Confused with net income, which again is a tax-return concept |
| Total compensation | Gross pay plus the value of benefits you provide | Sometimes quoted in offers, which inflates the apparent salary |
The base salary versus gross pay distinction is the one that causes offer-stage misunderstandings. If you tell someone their base salary is $60,000 and they also earn commission, their gross pay in a good month is higher than base and in a bad month equals it. Those are different numbers and both are gross.
The total compensation line deserves a warning. Quoting a total compensation figure that bundles in the value of health insurance and a retirement match is legitimate, and it is also how a $60,000 job gets described as an $80,000 opportunity. If you do it, be explicit about what is in the number, because an employee who hears $80,000 and receives $1,752 biweekly has been misled even if every figure was technically true.
Where They Work Matters
Two employees with identical gross pay, identical W-4s, and identical benefit elections can take home meaningfully different amounts, purely because of where they work. This is the section the competition skips almost entirely.
| State situation | Effect on net pay | What it means for you |
|---|---|---|
| Nine states levy no tax on wage income | Employee keeps notably more of the same gross | Alaska, Florida, Nevada, New Hampshire, South Dakota, Tennessee, Texas, Washington, Wyoming |
| Most states levy income tax | A flat rate or progressive brackets | You must register to withhold in every state where an employee works |
| Some cities levy local income tax | A further reduction in net pay | A handful of cities. Easy to miss entirely if you are not looking |
| Some states run disability or paid leave programs | Employee contributions come out of gross | Payroll-funded state programs with their own contributions and filings |
| Unemployment tax rates vary by state | No effect on net pay. Big effect on your cost | SUTA is employer-paid and experience-rated. Your claims history moves it |
One employer cost that is not on that table but belongs in the same budget line is workers' compensation insurance, which is a state mandate rather than a payroll tax and varies enormously by job class.
The operational consequence is bigger than the arithmetic. Withholding follows the employee's work location, not your office. Hire one person who works remotely from another state and you have created a new state withholding registration, a new unemployment account, and a new set of filing deadlines, none of which existed the week before. That is not a net pay issue; it is a compliance issue that arrives disguised as one.
Reading a Pay Stub
Most states require you to give employees an itemized pay stub, and most specify what has to be on it. Beyond compliance, a stub the employee can actually read is the single best answer to the question this whole article is about.
Letting employees retrieve their own stubs and W-2s through an employee self-service portal removes an entire category of request, and it means the person who wants to check a number can just go and check it.
The test of a good pay stub is simple: can the employee reconstruct the number in their bank account from it, unaided? If they can, most questions never get asked. If they cannot, you will be answering them personally, and the itemization requirements in some states carry per-employee penalties for getting it wrong.
Working Backwards
Occasionally you need to run this in reverse: you want to guarantee an employee a specific net amount, typically for a bonus or a relocation payment. This is called grossing up, and it is harder than it looks.
The basic idea is to divide the desired net by one minus the combined tax rate. Promise a $1,000 net bonus, and with a flat 22 percent federal supplemental rate plus 6.2 percent Social Security and 1.45 percent Medicare, the combined rate is 29.65 percent. So the gross payment is $1,000 divided by 0.7035, which is about $1,421.
The honest advice: avoid promising net figures unless you have a specific reason. Offer in gross, explain what net will roughly be, and you have avoided a calculation that is genuinely easy to get wrong and awkward to correct afterwards.
The First Paycheck
A new hire's first paycheck is frequently the strangest one they will ever receive from you, and it is the one most likely to generate a worried message. Almost always, nothing is wrong.
| Why it looks odd | What is actually happening | What to say |
|---|---|---|
| It is smaller than expected | They started mid-period, so it covers only the days they worked | Tell them at offer stage. This is the single most common first-check question |
| Withholding looks high | No W-4 on file means withholding as single with no adjustments | Collect the W-4 before day one, not after the first run |
| No health deduction appears | The benefit has not started yet, or enrollment is not complete | Explain that the deduction will begin, and that they are not getting it free |
| A double deduction appears later | A missed benefit deduction being caught up | Warn them before the run, not after they see it |
| No retirement deduction | Enrollment not yet processed, or a waiting period applies | Say when it starts. Otherwise they assume you forgot |
| It arrived a day late | Direct deposit takes days to settle, not seconds | Learn your bank's lead time and build the calendar backwards from payday |
Every row in that table is preventable with one sentence said in advance. The first row alone accounts for most first-check confusion: someone who starts on the 20th and is paid on the 30th is paid for ten days, not for a full period, and if nobody told them that the number looks like a mistake.
The W-4 row is the one with a real consequence. No W-4 does not mean no withholding. It means withholding at the default, which is single with no adjustments, and that is usually more than the employee expected rather than less. Collecting the W-4 during onboarding rather than chasing it afterwards removes the problem entirely.
Explaining It to Employees
You will have this conversation. Having it well, once, prevents having it badly several times.
The offer-stage conversation belongs in your standard process rather than depending on someone remembering it. Where compensation is explained, and what a new hire is told before day one, is part of new hire paperwork and worth writing into the employee handbook.
The second item is the one I would insist on. Every time I have tried to explain withholding in the abstract, it has failed. Every time I have opened the person's actual pay stub and pointed at their actual numbers, it has taken about four minutes and ended with them satisfied. The abstraction is the problem, not the concept.
Common Mistakes
Six recurring errors, and two of them are genuinely expensive.
The first is the expensive one for you. The last is the expensive one for the relationship, and it is entirely free to fix: a single sentence at offer stage removes the entire problem.
Most of these are arithmetic-in-a-spreadsheet failures, which is the strongest practical argument for payroll automation: not that the software is clever, but that it applies the correct base to the correct tax every single time without being reminded.
The 401(k) and FICA point is the one that produces quietly incorrect payroll. If your spreadsheet subtracts the retirement contribution before calculating Social Security, you have under-withheld FICA all year for that employee, and you will find out at reconciliation or you will not find out at all. It is a small error that compounds, and it is precisely the class of thing a payroll system does correctly and a person does not.
Frequently Asked Questions
What is the difference between gross pay and net pay?
Gross pay is the total an employee earned before anything is taken out. Net pay is what actually reaches their bank account after every deduction. The formula is simple: gross pay minus deductions equals net pay. The deductions in between include federal income tax, Social Security at 6.2 percent, Medicare at 1.45 percent, state and sometimes local income tax, plus voluntary items such as retirement contributions and health insurance premiums. For a typical US employee, net pay lands somewhere around 70 to 80 percent of gross, though the exact figure depends heavily on their state, their W-4, and what benefits they have elected.
Is net pay the same as gross pay?
No. They are never the same for an employee, because taxes are always withheld from wages. Gross pay is the larger number, and it is the one in the offer letter and at the top of the pay stub. Net pay is the smaller number, and it is the one at the bottom, and it is the only one the employee can actually spend. The gap between them is typically 20 to 30 percent of gross. The only way the two figures would match is if no tax and no deduction applied at all, which does not happen with employee wages.
Is net pay before or after taxes?
After. Net pay is what remains once all taxes and deductions have been subtracted, which is why it is also called take-home pay. Gross pay is the before-tax figure. If you find the terms hard to keep straight, the useful mnemonic is that gross is gross because it is the big, unrefined number, and net is what you actually catch. Everything an employer discusses in a salary negotiation is gross; everything an employee experiences in their bank account is net.
What is the relationship between gross pay and net pay?
Net pay is derived from gross pay by subtraction. Gross pay is the starting point of every payroll calculation, and net pay is the output. Everything in payroll is computed from gross: withholding percentages apply to it, the Social Security wage base is measured against it, and the employer's own tax contributions are calculated on it. Net pay is simply what is left when the arithmetic is done. This means net pay is never an input you choose; it is a result. If you find yourself trying to work backwards from a target net figure, that is a distinct exercise called grossing up, and it is harder than it looks.
Is base salary gross or net?
Gross, always. When you offer someone $60,000 a year, you are offering $60,000 of gross pay. They will not receive $60,000; they will receive that amount minus federal income tax, Social Security, Medicare, state tax where applicable, and any benefit deductions they elect. This is worth being explicit about in an offer conversation, because a candidate who mentally spends the gross figure and then sees the net figure on their first pay stub has had a disappointing experience that a single sentence from you could have prevented.
Why is my employee's net pay lower than they expected?
Almost always because they were thinking in gross. Between the offer letter figure and their bank account sit federal income tax, Social Security at 6.2 percent, Medicare at 1.45 percent, state income tax in most states, and whatever they elected for retirement and health coverage. Together these commonly remove 20 to 30 percent of gross. A secondary cause is a new W-4 that withholds more than they anticipated, particularly if they checked the multiple-jobs box. If an employee raises this with you, walk them through their own pay stub line by line rather than explaining it in the abstract.
How do you calculate gross pay?
For a salaried employee, divide the annual salary by the number of pay periods in your year: 26 for biweekly, 24 for semimonthly, 52 for weekly, 12 for monthly. A $60,000 salary on a biweekly schedule produces gross pay of $2,307.69 per period. For an hourly employee, multiply hours worked by the hourly rate, and add overtime at one and a half times the regular rate for any hours over 40 in a workweek. Then add any bonuses, commissions, tips, or shift differentials earned in the period. That total is gross pay, and every subsequent calculation flows from it.
How do you calculate net pay?
Start from gross pay and subtract in the correct order. First, pre-tax deductions such as traditional retirement contributions and Section 125 health premiums, because they reduce the wages that tax is calculated on. Second, federal income tax using the employee's W-4 and the current IRS withholding tables. Third, Social Security at 6.2 percent up to the annual wage base and Medicare at 1.45 percent with no cap. Fourth, state and any local income tax. Fifth, post-tax deductions such as Roth contributions and garnishments. What remains is net pay. The order matters, because taking a pre-tax deduction after calculating tax produces the wrong answer.
What deductions come out of gross pay?
Mandatory ones and voluntary ones. Mandatory: federal income tax, Social Security, Medicare, state income tax in all but nine states, any local income tax, and court-ordered garnishments. Voluntary: retirement contributions, health, dental and vision premiums, HSA and FSA contributions, life and disability insurance, commuter benefits, and union dues. Voluntary deductions split further into pre-tax, which reduce taxable wages, and post-tax, which do not. That pre-tax versus post-tax distinction is what determines whether a deduction saves the employee money on tax, and it is not uniform even within a single category.
Do employers pay taxes on gross pay too?
Yes, and this is the number that never appears on the pay stub. On top of the employee's gross pay, the employer pays a matching 6.2 percent for Social Security and a matching 1.45 percent for Medicare, which together is 7.65 percent of wages. Employers also pay federal unemployment tax, which is 6.0 percent on the first $7,000 of each employee's wages but is usually reduced to an effective 0.6 percent by a credit for paying state unemployment tax, plus state unemployment tax which varies by state and by claims history. None of this is deducted from the employee. It is a cost of employing them.
Does gross pay include overtime and bonuses?
Yes. Gross pay is everything the employee earned in the period, which includes regular wages, overtime, bonuses, commissions, tips, and shift differentials. All of it is subject to Social Security and Medicare, and all of it is subject to income tax. Bonuses are withheld differently, since the IRS treats them as supplemental wages and permits a flat 22 percent federal withholding rate when they are paid separately, but that is a difference in withholding method rather than in tax liability. It is all wages, and it all sits in gross pay.
What is the gross pay to net pay ratio?
For a typical US employee, net pay lands somewhere between 70 and 80 percent of gross, but the range is genuinely wide and the number is not a useful planning figure on its own. Someone in a state with no income tax, contributing nothing to a retirement plan, keeps a much larger share than someone in a high-tax state contributing 10 percent to a 401(k) and paying a family health premium. The only reliable way to know is to run the actual calculation with the employee's actual W-4, their actual state, and their actual elections.
What is grossing up?
Grossing up is working backwards from a desired net figure to find the gross payment required to produce it after tax. If you promise an employee a $1,000 net bonus, you have to pay more than $1,000 gross so that the withholding leaves exactly $1,000. The basic approach is to divide the desired net by one minus the combined tax rate. It is more complicated than it sounds, because the employer covering the employee's tax is itself additional taxable income, and the calculation can iterate. If you are grossing up anything material, use payroll software or ask your accountant rather than doing it by hand.
Why did my employee's paycheck suddenly get bigger?
They almost certainly crossed the Social Security wage base, which is $184,500 for 2026. Once an employee's year-to-date wages exceed that figure, you stop withholding the 6.2 percent Social Security tax for the rest of the calendar year, and their net pay rises by 6.2 percent of gross. Medicare has no wage base and continues on every dollar, so the increase is 6.2 percent rather than the full 7.65 percent. Your employer match stops at the same point, which is one of the few places your cost per employee actually falls. It all resets on January 1, and their pay drops back.
Does the employer match the Additional Medicare Tax?
No. You must withhold the 0.9 percent Additional Medicare Tax on an employee's wages above $200,000 in a calendar year, and you must begin in the pay period in which their wages cross that figure and continue for the rest of the year. But there is no employer match on it, unlike the regular 6.2 percent and 1.45 percent which you do match. The full 0.9 percent comes out of the employee. Note also that you withhold based on wages from you alone, regardless of the employee's filing status; their actual liability depends on their household and is reconciled on their tax return.
Do contractors have gross and net pay?
No. A contractor has one number. You pay the invoiced amount in full, with nothing withheld: no income tax, no Social Security, no Medicare. You also pay nothing on top, meaning no employer FICA match and no unemployment tax. They receive their gross and handle their own self-employment tax. That is why gross and net pay exist only in employment: withholding is a feature of the employer-employee relationship. It is also why misclassifying an employee as a contractor is tempting and expensive, because the apparent saving is not a saving but a liability.
What is the difference between gross pay and gross income?
Gross pay is a payroll term: the total an employee earned from you in a pay period, before deductions. Gross income is a tax-return term: all income the person received from every source, including wages, self-employment, investments, and rental income. They are related, since wages feed into gross income, but they are not interchangeable. Gross pay appears at the top of a pay stub. Gross income appears on a tax return. An employee asking about gross income is usually asking a question their accountant should answer rather than one you should.
Why is a new hire's first paycheck smaller than expected?
Usually because they started mid-period, so the check covers only the days they actually worked rather than a full pay period. Someone who starts on the 20th and is paid on the 30th is paid for ten days. The second most common cause is that no Form W-4 was on file, in which case withholding defaults to single with no adjustments, which is typically more than the employee anticipated rather than less. Both are avoidable by saying so in advance and by collecting the W-4 before day one instead of after the first payroll run.
Does an employee's state affect their net pay?
Substantially. Nine states levy no tax on wage income at all, which means an employee there keeps meaningfully more of the same gross salary than an identical employee elsewhere. Other states have flat rates, some have progressive brackets, and a handful of cities levy their own local income tax on top. This matters to an employer beyond the arithmetic, because the state where an employee actually works, not where your office is, determines which withholding rules apply, and hiring one remote person in a new state creates registration and filing obligations there.