How to Calculate Bi-Monthly Pay: Gross, Net, and Overtime

To calculate semi-monthly pay, divide your annual salary by 24 to get gross pay per check, or for hourly work multiply your rate by the hours logged in each half-month (or by 2,080 and divide by 24 for a smoothed figure). Then subtract 7.65% for FICA, your federal income tax withholding, any pre-tax benefits like a 401(k) or health premiums, and your state and local taxes. What lands in your account is usually 70–80% of the gross.

The rest is knowing which numbers go where, and why a few of them behave in ways the simple formula doesn’t show.

First, Confirm You’re Actually on a Semi-Monthly Schedule

Semi-monthly and biweekly are not the same thing, and using the wrong divisor throws off every number downstream. Semi-monthly means two fixed calendar dates each month, typically the 15th and the last day, for 24 paychecks a year. Biweekly means every 14 days, usually the same weekday, for 26 paychecks a year.

A $60,000 salary divided by 24 is $2,500 per check. Divided by 26 it’s about $2,308. Before you calculate anything, ask payroll whether you get 24 or 26 checks a year.

Gross Pay for Salaried Workers

For a salaried employee, the calculation is one step: annual salary ÷ 24.

  • $48,000 salary: $2,000 per paycheck
  • $60,000 salary: $2,500 per paycheck
  • $72,000 salary: $3,000 per paycheck
  • $90,000 salary: $3,750 per paycheck

The amount stays the same whether the month has 28 or 31 days. That predictability is a big part of why employers put salaried staff on this schedule.

Gross Pay for Hourly Workers

Hourly workers on a semi-monthly cycle can be paid one of two ways, and which one your employer uses decides whether your check varies from period to period.

Actual Hours Worked

Most employers pay for the exact hours logged between the 1st and the 15th, then between the 16th and the last day of the month. At $25 per hour, 88 hours in the first half of January comes to $2,200 gross; 80 hours in the second half comes to $2,000. Halves of a month aren’t equal, so the checks won’t be either.

When you’re totaling hours, short rest breaks of 20 minutes or less count as paid work time under federal law. Meal breaks of 30 minutes or more can be unpaid, but only if you’re completely relieved of duties. If you have to watch a phone or stay at your station, that time should show up as paid on your stub.1U.S. Department of Labor Wage and Hour Division. Fact Sheet #22: Hours Worked Under the Fair Labor Standards Act (FLSA)

Annualized Average (Hourly Rate × 2,080 ÷ 24)

Some employers smooth the calendar variation by annualizing first. The formula: hourly rate × 2,080 ÷ 24. The 2,080 comes from 40 hours per week for 52 weeks. Federal payroll uses 2,087 to account for years with extra workdays, but private employers usually round to 2,080.2U.S. Office of Personnel Management. Computing Hourly Rates of Pay Using the 2,087-Hour Divisor

At $30 per hour: $30 × 2,080 = $62,400 ÷ 24 = $2,600 per check. The number is consistent, though your employer may reconcile at year-end if your actual hours came in above or below 2,080.

Overtime and the Workweek Straddle

Overtime is the piece of semi-monthly payroll that trips people up. Federal law requires 1.5 times your regular rate for every hour beyond 40 in a single workweek.3Office of the Law Revision Counsel. 29 U.S. Code 207 – Maximum Hours A workweek is a fixed seven-day cycle, and it almost never aligns with a semi-monthly cutoff.4eCFR. Determining the Workweek

Say your workweek runs Sunday through Saturday and the 15th falls on a Wednesday. The workweek that started the previous Sunday now straddles two pay periods. Your employer still owes overtime on the full seven-day week, but can wait to pay those hours on the paycheck that covers the period where the workweek actually ends.5GovInfo. 29 CFR 778.106 – Time of Payment If your stub ever looks off by a few overtime hours, this straddle is usually why.

The Deductions That Shrink Gross to Net

Gross pay is the easy number. What actually hits your account depends on four layers of withholding.

FICA: Social Security and Medicare

Two federal payroll taxes come out of every check under the Federal Insurance Contributions Act, with no W-4 lever to change them.6Internal Revenue Service. Topic No. 751, Social Security and Medicare Withholding Rates

  • Social Security: 6.2% of gross wages, up to $184,500 in total earnings for 2026. Once you hit that ceiling, Social Security withholding stops for the rest of the year.7Social Security Administration. Social Security Tax Limits on Your Earnings
  • Medicare: 1.45% of all gross wages, no cap. Wages above $200,000 for the year trigger an additional 0.9% Medicare surtax that your employer must withhold on the excess.8Internal Revenue Service. Questions and Answers for the Additional Medicare Tax

On a $2,500 gross check, that’s $155 for Social Security and $36.25 for Medicare, or $191.25 combined. FICA takes 7.65% of gross pay for most workers.

Federal Income Tax

Federal income tax withholding is set by the filing status and adjustments on your Form W-4.9Internal Revenue Service. Topic No. 753, Form W-4, Employees Withholding Certificate Unlike FICA, it’s progressive: higher slices of income are taxed at higher rates. For 2026 the brackets run from 10% on the first $12,400 of taxable income for a single filer up to 37% on income above $640,600.10Internal Revenue Service. IRS Releases Tax Inflation Adjustments for Tax Year 2026

If your withholding looks off, filing a new W-4 changes future paychecks. Too little withheld means a bill and possible penalty at tax time; too much means an interest-free loan to the government.11Internal Revenue Service. Form W-4 (2026) Employees Withholding Certificate

Pre-Tax Deductions Change the Order of Operations

Certain deductions come out of gross before federal income tax is calculated, which lowers the wages your employer runs through the bracket math. The common ones:

One trap: traditional 401(k) contributions lower your income for federal income tax purposes but don’t lower FICA wages. You still pay Social Security and Medicare on the full gross. HSA contributions through payroll reduce both federal income tax wages and FICA wages.

State and Local Taxes

Most states withhold their own income tax on top of the federal amount. Eight states have no income tax; top marginal rates elsewhere run up to roughly 13%. Some cities and counties add a local income tax, and a handful of states require employee contributions to state disability insurance or paid family leave, typically below 1.5% of wages. Your state labor department publishes the rates and wage caps that apply where you work.

A Worked Example, End to End

Here’s how the pieces fit for a single filer earning $60,000 a year, contributing 6% to a traditional 401(k), and paying $150 per check toward employer-sponsored health insurance run through a cafeteria plan:

  • Gross semi-monthly pay: $60,000 ÷ 24 = $2,500.00
  • Health insurance (pre-tax, cafeteria plan): −$150.00
  • 401(k) at 6%: −$150.00
  • Social Security, 6.2% of $2,350*: −$145.70
  • Medicare, 1.45% of $2,350*: −$34.08
  • Federal income tax (estimate, varies by W-4): −$175.00
  • Approximate net pay: about $1,845

*Cafeteria-plan health premiums reduce FICA wages to $2,350. The 401(k) contribution does not, so Social Security and Medicare are still calculated on $2,350, not $2,200. State and local taxes would reduce the net further.

The federal income tax line is an approximation; your actual withholding depends on your W-4, other income, and credits. The structure is what matters: it’s why take-home usually runs 70–80% of gross, and why the order of deductions changes the answer.

When Payday Falls on a Weekend or Holiday

Fixed calendar dates mean the 15th or the last day of the month sometimes lands on a Saturday, Sunday, or bank holiday. Federal law doesn’t require your employer to pay early when that happens.14U.S. Department of Labor. Holiday Pay Most employers with direct deposit move the payment to the preceding business day; some push it to the next one. If a bill is due on the 15th and your company pays on the following Monday, that gap can cost a late fee. Ask your payroll department which direction they move the date, and set your bill autopays accordingly.