First Paycheck Calculator

How your first payday is set

A paycheck pays for a pay period that has already closed. Payroll totals the period's hours, and payday comes a set number of days after the period ends. That gap is the lag, and it's why your first check comes days or weeks after your first shift.

Take the default example above. A biweekly pay period runs from Sunday, October 25 to Saturday, November 7, 2026, and you start on Monday, November 2, so that period holds 5 of your workdays. Payday is 6 days after the period closes, on Friday, November 13: 11 days after your first shift. If your employer pays one week further behind (a 13-day lag), the period you start in runs November 1 to 14 instead. Your first check is then a full one, but it comes on November 27, 25 days after you start.

Weekly and biweekly paydays always land on the same weekday, so one payday from your offer letter or HR fixes the whole schedule. Semimonthly and monthly periods follow the calendar instead (the 1st to the 15th and the 16th to the end of the month, or the whole month), and a payday that lands on a weekend moves to the Friday before or the Monday after, depending on the employer. On a semimonthly schedule paid 5 days after each period ends, the November 16 to 30 period's payday falls on Saturday, December 5, so an employer that pays the Friday before pays it on Friday, December 4.

Then there's the payroll cutoff. A new hire entered after a period's payroll closes gets paid on the next run. Texas A&M University–Corpus Christi's payroll FAQ gives an example for its monthly-paid staff: "if you are hired with a start date of 8.26.2025, this would be after the August monthly payroll calculated. You will have missed the August monthly payroll, which pays on 9.03.2025. The 5 days you worked in August would be paid to you when you receive your September paycheck on 10.01.2025."

How soon you must be paid depends on your state. The U.S. Department of Labor keeps a table of state payday requirements. California, for example, requires weekly and biweekly wages, and semimonthly wages for periods other than the 1st to the 15th and the 16th to the end of the month, to be paid "within seven calendar days of the end of the payroll period within which the wages were earned" (California Labor Commissioner).

Why the first check is smaller, and why less tax comes out of it

The first check is short because it covers only the days you worked. In the default example you start on day 9 of a 14-day period and work 5 of its 10 weekdays: 40 hours, against 80 on the next check. Start on the Wednesday instead and it's 24 hours. Here are the two checks side by side ($20 an hour, 8 hours Monday to Friday, single, Illinois):

Half the hours, but about a sixth of the federal withholding. That comes from how payroll works out the tax. Under the percentage method for automated payroll systems in IRS Publication 15-T, the employer multiplies the check by the number of paydays in a year and treats the result as your annual pay:

1. $800.00 x 26 biweekly paydays = $20,800 a year.
2. Minus the $8,600 Worksheet 1A adjustment for a single filer = $12,200.
3. The single table withholds 10% of the part over $7,500: ($12,200 − $7,500) x 10% = $470.00 a year.
4. Divided back by 26, that's $18.08 for this check.

Run the full $1,600.00 check the same way and it annualizes to $41,600, or $33,000 after the adjustment, which reaches the 12% row: $1,240 + ($33,000 − $19,900) x 12% = $2,812.00 a year, or $108.15 a check. A $480.00 Wednesday-start check annualizes to $12,480, which leaves $3,880 after the adjustment, under the $7,500 where withholding starts, so nothing comes out at all.

A lower rate on the first check doesn't mean you owe less tax. Withholding is a prepayment. Your real tax is worked out on your return, where all of the year's checks count together (IRS Publication 505). Social Security and Medicare don't annualize at all: they're a flat 6.2% and 1.45% of every check, short or full, so they shrink only with your gross.

Missed the cutoff? The later, bigger first check

If your start is entered after payroll closes, the hours from your first period wait for the next payday and arrive together with the next period's. In the default example, nothing comes on November 13. On November 27 you get one check for 120 hours: $2,400.00 gross.

Payroll withholds on that check as if it were one period's pay. IRS Publication 15 says that when supplemental wages are paid with regular wages and the two amounts aren't specified, the employer withholds "as if the total were a single payment for a regular payroll period." The flat 22% option for pay that is identified separately is open only to an employer that withheld from your regular wages in the current or the previous calendar year, and a new employer hasn't. Either way, the whole check is annualized: $2,400 x 26 = $62,400.

That puts $204.15 of federal income tax on the combined check. On time, the two checks would have had $18.08 and $108.15 withheld, $126.23 in all, so combining adds $77.92 of federal withholding, plus $5.57 of Illinois tax: $83.49 in all. Start on the Wednesday and miss the cutoff, and the extra federal withholding is $57.60. Like any over-withholding, the extra counts toward your 2026 tax and comes back in a refund if you've paid too much.

The bigger cost is the wait. In that example 25 days pass between your first shift and your first money, against 11 if you'd made the cutoff. If you can, ask HR which payroll your start date makes, and plan your first month around the later date.

What this estimate leaves out

The calculator sticks to timing and partial-period pay. It leaves out benefit and 401(k) deductions: if yours start after a waiting period, your first checks may have fewer deductions than later ones. Federal withholding covers a W-4 with only a filing status, so Steps 2 to 4 (multiple jobs, dependents, other income and extra withholding) aren't in it. The W-4 withholding calculator covers those. State tax is an estimate from each state's 2026 schedule, not its withholding formula, and local income taxes, SDI and paid-leave contributions aren't included. Holidays aren't modeled, and neither is an off-cycle check for missed hours.

To watch your real first check take shape, log each shift on the ClockWage44 week grid from your first day. The paycheck editor opens on the current pay period and shows the take-home live as the hours add up, with the state, filing status and pay period from your Tax Profile.