- Every period is derived from the annual figure, so the numbers on screen always reconcile back to the same salary.
- Biweekly is 26 checks a year and semi-monthly is 24 — the same salary makes a bigger semi-monthly check.
- Hourly and daily rates depend on the schedule; unpaid weeks raise the hourly rate a salary implies.
- Net pay per period is the annual net split evenly — real checks grow late in the year once Social Security stops being withheld.
How the salary converter works
Every period is derived from one annual figure. Whatever you enter is converted to a yearly amount first, then divided back down — so the hourly, weekly and biweekly numbers on screen always multiply back to the same salary, which is not true of a chain of conversions that rounds at each step.
Two of the periods are calendar-based rather than schedule-based. Biweekly pay means 26 checks a year, because 52 weeks divides evenly into 26 fortnights. Semi-monthly means 24, because it is twice a month regardless of how the weeks fall. That is why the same salary produces a bigger semi-monthly check than a biweekly one, and why two people on identical salaries can see different amounts landing on the same day.
The hourly and daily figures depend on the schedule you set. The default is a 40-hour week over 52 paid weeks; drop the weeks if you are on a contract with unpaid time, and the hourly rate rises to match.
The math
Annual pay is the amount you enter multiplied by the number of those periods in a year: 52 weeks, 26 fortnights, 24 semi-monthly checks, 12 months, or hours per week times paid weeks for an hourly rate. Every other period is that annual figure divided by its own count.
The net side runs the annual figure through the same tax engine as the income-tax calculators: the federal standard deduction, the federal brackets, your state’s own schedule and deduction, then Social Security up to the annual wage base and Medicare on the full amount.
One caveat about the net per-period figures: they are the annual net divided evenly. Real payroll withholds Social Security until you reach the wage base and then stops, so high earners see larger checks late in the year than the even split shown here. The annual total is right; the month-to-month rhythm is smoother than reality.
Worked example
Take $36 an hour at 40 hours a week over 52 weeks. That is $74,880 a year, $6,240 a month, $3,120 semi-monthly, $2,880 biweekly and $1,440 a week — note that the semi-monthly check is $240 larger than the biweekly one purely because there are two fewer of them.
Drop to 48 paid weeks — four unpaid — and the same hourly rate becomes $69,120 a year, a $5,760 difference. On the net side, the tax saved on that lost income only returns about a quarter of it, which is why unpaid weeks cost more than they look like they should when you are pricing contract work against a salaried offer.
Key terms
- Biweekly
- Paid every two weeks — 26 checks a year. Two months a year contain three of them, which is where the “extra” check comes from.
- Semi-monthly
- Paid twice a month — 24 checks a year, usually mid-month and month-end. Larger than a biweekly check on the same salary.
- Gross pay
- What you earn before anything is withheld. The figure quoted in an offer letter and the one every conversion here starts from.
- Net pay
- What lands in your account after income tax and payroll withholding. The number worth comparing between two offers.