Biweekly vs semimonthly pay: how to tell which a stub is
Biweekly pay is every two weeks, on the same weekday, which gives 26 pay dates in most years. Semimonthly pay is twice a month on fixed calendar dates, such as the 15th and the last day, which gives 24. On a stub, a 14-day pay period means biweekly, while periods that run the 1st to the 15th and the 16th to month-end mean semimonthly.
Published . General information, not lending, legal or tax advice.
Two schedules that sound alike
Biweekly means every two weeks. The pay date lands on the same weekday each time, so 26 pay dates fall in most years and an occasional year has 27. Semimonthly means twice a month on set calendar dates, commonly the 15th and the last day or the 1st and the 16th, so there are always 24.
The difference matters because one stub converts to different monthly income under each schedule. A $1,800 stub is $3,900 a month if biweekly (× 26 ÷ 12) and $3,600 if semimonthly (× 24 ÷ 12), a $300 swing from one misread. Monthly income from pay stubs has the full conversion.
How to tell from the dates on a stub
Use the pay period dates first and the pay dates second.
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Read the pay period start and end
Most stubs print them as pay period or period beginning and ending. The pay date is when the money was issued, and it can fall a few days after the period closes.
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Count the days in the period
Fourteen days from start to end, counting both, is biweekly, and seven is weekly. A period running from the 1st to the 15th, or from the 16th to month-end, is semimonthly.
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Compare three or more pay dates
Biweekly pay dates are always exactly 14 days apart and share a weekday. Semimonthly gaps vary between about 13 and 16 days and share calendar dates instead.
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Allow for the weekend rule
Semimonthly pay dates that land on a weekend or holiday usually move to a nearby business day, so the weekday varies while the period dates stay put.
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Test the year to date
If pay is steady, YTD gross divided by one stub's gross should be close to the number of pay dates so far, and that count should match the schedule.
Biweekly and semimonthly side by side
The points that differ in practice, with the same example salary in the last row.
| Aspect | Biweekly | Semimonthly |
|---|---|---|
| Pay dates a year | 26 in most years, 27 in some | 24, always |
| Pay period | 14 days, start to end | 1st to 15th and 16th to month-end, so 13 to 16 days |
| Pay date pattern | Same weekday, every 14 days | Same calendar dates, moved off weekends and holidays |
| Months with an extra check | Two a year have three pay dates, in a 26-date year | None: two every month |
| Monthly income from one stub | Gross × 26 ÷ 12, about 2.17 times the stub | Gross × 2 |
| Gross per stub on a $78,000 salary | $3,000.00 | $3,250.00 |
What goes wrong
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A label that contradicts the dates
A stub printed 'semi-monthly' with 14-day periods is on a biweekly schedule. Go by the dates, and note the discrepancy in the file.
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Only pay dates are printed
One gap of 14 days fits biweekly, but a semimonthly gap in February can be 13 or 14 as well. Three or more stubs settle it, because biweekly gaps are all exactly 14.
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A schedule that changed mid-year
Employers sometimes move from biweekly to semimonthly, or back. YTD carries on, but averaging stubs across the switch mixes two period lengths.
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A 27th pay date
In some years a biweekly calendar has 27 pay dates. How salaried pay is spread across them differs by employer, so a year-end YTD can run higher than 26 stubs' worth. YTD income verification covers reading those totals.
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A holiday-shifted pay date read as a missing stub
A pay date that moves for a holiday does not change the pay period. Check the period dates before calling a stub late. Missing pay stub periods covers the check.
How VerifyStub helps
VerifyStub reads the period dates on each stub and sets the frequency from them: 14 days is biweekly, 7 is weekly, and the 1st to the 15th or the 16th to month-end is semimonthly. When period dates are not printed it falls back to the frequency printed on the stub, then to the spacing of pay dates, and a warning says the period dates were not read. The frequency has its own CSV column and drives the pay periods per year and the missing-period check. It reports, and you decide. Try the pay stub to CSV page (free: 1 file per day, up to 10 pages, no account) or see pricing.
Scope. VerifyStub checks arithmetic on the pay stubs you upload. It does not detect altered documents, verify employment or income, or give lending, legal or tax advice. Rules and policies differ by lender, program, landlord and jurisdiction.
Biweekly vs semimonthly pay: common questions
Is biweekly the same as twice a month?
No. Biweekly is every two weeks, which gives 26 pay dates in most years. Twice a month is semimonthly, which gives 24. They are easy to confuse, and they change the monthly income worked out from a stub.
How many pay periods are there in a year for each schedule?
Biweekly has 26 in most years and occasionally 27. Semimonthly has 24, weekly has 52 and monthly has 12. The monthly income conversion uses these counts, so identifying the schedule correctly comes first.
What does bimonthly mean on a pay stub?
It is ambiguous. Some payers mean twice a month and others mean every two months. Do not rely on the word. Read the period dates, and note which meaning they support.
Why do some months have three biweekly paychecks?
In a year with 26 pay dates, two months contain three of them. Monthly income is unchanged. Those months simply show an extra deposit.
Which schedule pays more?
Neither. A $78,000 salary pays $3,000 per biweekly stub or $3,250 per semimonthly stub, and $6,500 a month either way. Only the size and timing of each check differ.
How do I find the schedule if the stub shows only pay dates?
Compare three or more pay dates. Biweekly gaps are always 14 days on the same weekday. Semimonthly gaps vary from about 13 to 16 days on the same calendar dates.
What if the employer changed the pay schedule during the year?
Use stubs from the current schedule for any per-period calculation. YTD totals carry across the switch, but averaging stubs from both schedules blends two period lengths.
Does the pay date or the pay period decide the frequency?
The pay period. Pay dates can move for weekends and holidays or trail the period by several days, while the period dates follow the schedule.
Keep reading
Related guides, or all of the pay stub guides.
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Monthly income from pay stubs
The formula for weekly, biweekly, semimonthly and monthly stubs, with a worked table and the shortcuts that understate income.
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Missing pay stub periods
How a gap shows up in the dates and the YTD, what to request, and what is not a gap.
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YTD income verification
What year-to-date figures on a pay stub show as a pace check, and why they are not verification.
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