Semi-Monthly Pay Calculator
Convert pay between weekly, fortnightly, semi-monthly, monthly and annual — including the two extra fortnightly pays a year that budgets forget.
Semi-monthly means twice a month — 24 pays a year.
How the semi-monthly pay calculator works
Semi-monthly means twice a month — 24 pays a year. Fortnightly means every two weeks — 26 pays. They are not the same, and the difference is the source of a great deal of budgeting confusion.
Budgeting a fortnightly salary as though it were "twice monthly" leaves two whole pay periods a year unaccounted for. Those two extra pays are the ones people find surprizing in the months where three arrive.
Formula: annual = per-period × periods per year
Worked examples
| Inputs | Annual pay | Note |
|---|---|---|
| 3,200 semi-monthly | $76,800.00 | 76,800 a year |
| The same amount fortnightly | $83,200.00 | 83,200 — two extra pays |
| From an annual salary | $90,000.00 | every other frequency |
FAQFrequently asked questions
What is the difference between semi-monthly and fortnightly?
Semi-monthly is twice a month — 24 pays a year. Fortnightly is every two weeks — 26. They are not interchangeable.
Why do I sometimes get three pays in a month?
Because 26 fortnightly pays do not divide evenly into 12 months. Two months a year contain three.
How should I budget for that?
Budget on the fortnightly amount times 26 divided by 12, not on "twice a month". The two extra pays are then a planned surplus rather than a surprize.
Which is better for a worker?
Fortnightly delivers the same annual amount in more, smaller instalments. Cash flow is smoother; the total is identical.
Does this account for tax?
No. These are gross conversions. Tax withheld per period depends on your market's rules and on the frequency itself.
Where these figures come from
- CFA Institute — Quantitative Methods: The Time Value of Money — the discounting, annuity and IRR conventions used here
- US Federal Reserve — Regulation Z (Truth in Lending), APR calculation — why APR includes fees where a nominal rate does not
- Consumer Financial Protection Bureau — the US consumer finance regulator
Last checked: September 2026. These are the standard textbook formulas; the conventions named are those of the CFA Institute curriculum and ISO 80000 usage.