How this calculator compares the two schedules
Both schedules pay the same yearly salary. The calculator divides it by 26 for biweekly and by 24 for semi-monthly, then runs each paycheck through the same 2026 calculation as the take-home pay calculator: federal income tax withholding from the IRS Publication 15-T percentage method, Social Security, Medicare and your 401(k) percentage.
The calendar works out your biweekly paydays for 2026 from the payday you enter, by counting every 14 days across the year. A month has three paychecks when three of those paydays land in it.
Biweekly check = salary / 26 and Semi-monthly check = salary / 24
Worked examples
What the results mean
The semi-monthly paycheck is larger because it is one of 24, not one of 26. That is not extra pay. Over a full year you take home the same amount, within rounding. The yearly column assumes 26 biweekly checks. In a year with 27 biweekly paydays, ask your payroll team how the extra check is handled, because that depends on whether you are paid a salary or by the hour.
For hourly workers the schedule matters in a different way, because overtime is counted by the workweek. See semi-monthly vs biweekly pay for the overtime rule and a worked example.
2026 numbers used
| Item | 2026 figure |
|---|---|
| Social Security tax (employee) | 6.2% on wages up to $184,500 |
| Medicare tax (employee) | 1.45% on all wages |
| Additional Medicare Tax | 0.9% on wages above $200,000 in the year |
| Standard deduction behind the withholding tables | $16,100 single, $32,200 married filing jointly, $24,150 head of household |
| 401(k) employee limit | $24,500 ($32,500 age 50 and over, $35,750 ages 60 to 63) |
Assumptions and limits
- Pay is a flat yearly salary. The comparison uses a regular paycheck early in the year, without a bonus.
- Federal withholding uses the standard percentage method for a Form W-4 filed in 2020 or later. State and local taxes, other deductions and the Step 2 multiple jobs box are not included. Use the paycheck calculator for those.
- Semi-monthly means two paydays a month. The calculator does not move paydays that fall on a weekend.
- Your employer sets your schedule. Some states set minimum pay frequencies, so check with your state labor office.
Sources
Rules reviewed October 2026 against: IRS Publication 15-T (2026), Federal Income Tax Withholding Methods; IRS Publication 15 (2026), Employer’s Tax Guide; Social Security Administration, contribution and benefit base; IRS 2026 retirement plan limits; US Department of Labor, State Payday Requirements. Tax law and limits change, so confirm current figures with the IRS or a tax professional.
Frequently asked questions
Does biweekly or semi-monthly pay more?
Neither. Your yearly salary is the same. Biweekly splits it into 26 smaller checks and semi-monthly into 24 larger ones, so each semi-monthly check is about 8.33% bigger.
Why do I get a third paycheck in some months?
Biweekly pay has 26 paydays a year, which is two more than 24, so two months a year (sometimes three) have three paydays. Enter your first payday of 2026 above to see which months.
Is semi-monthly the same as biweekly?
No. Biweekly means every two weeks, on the same weekday. Semi-monthly means twice a month on set dates, usually the 15th and the last day.
Will my taxes change if my employer switches schedules?
Your yearly Social Security and Medicare tax stays the same, and your yearly federal income tax is nearly the same. Withholding is worked out per check, so the amount per check changes and small rounding differences can appear.
Does the schedule change my 401(k) contributions?
A percentage contribution gives the same yearly total either way. A flat dollar amount per check does not, because you make 26 contributions on a biweekly schedule and 24 on a semi-monthly one.