Prorated Salary Calculator
The period, the days worked and the convention
Your result will appear here
Fill in the fields on the left and this updates as you type.
Know what this estimate is based on
- Jurisdiction
- General mathematical model
- Scope and limitations
- Planning indicator only. It does not assess every part of a household's finances or replace individualized professional advice.
- Source links checked
- Jul 30, 2026
Built and regression-tested by Smart Tools Lab. It has not been individually reviewed by a licensed financial, tax, or legal professional.
How to use
- 01
Enter your annual salary, then the workdays in the semi-monthly period — typically 10, 11 or 12 depending on where the weekends fall — and the workdays you were actually employed and paid inside it.
- 02
Enter the calendar days you were employed inside the biweekly period. These are counted separately from the workdays on purpose: a biweekly payroll prorates on all 14 calendar days including the weekend, which is exactly why the two conventions disagree.
- 03
Enter your combined federal, state and FICA withholding rate to see the net, remembering that benefit premiums usually come out of a partial cheque in full rather than prorated.
- 04
Open Advanced for unpaid leave days inside the period, on top of the days before you started or after you left, and for the divisors: 24 semi-monthly periods, 26 biweekly, 2,080 annual hours and an 8-hour day.
- 05
Read the three methods side by side and the spread between them. Whichever one your employer uses is decided by a payroll system you do not control — so if the stub does not match your arithmetic, the divisor is what to ask about before assuming an error.
Formula
A full semi-monthly cheque = annual salary ÷ 24. A full biweekly cheque = annual salary ÷ 26. SEMI-MONTHLY, on workdays: prorated pay = the semi-monthly cheque × (workdays worked ÷ workdays in the period), where workdays worked has any unpaid leave days removed first. BIWEEKLY, on calendar days: prorated pay = the biweekly cheque × (calendar days worked ÷ 14). HOURLY EQUIVALENT: hourly = annual salary ÷ 2,080; prorated pay = hourly × workdays worked × 8. Spread = the highest of the three − the lowest. One workday is worth the semi-monthly cheque ÷ workdays in the period; one calendar day is worth the biweekly cheque ÷ 14. Net = the headline figure × (1 − withholding rate), before any benefit premium — which is usually taken in full rather than prorated.
Example
$78,000 a year, starting mid-period: 6 of the 11 workdays in the semi-monthly period, which is 8 of the 14 calendar days in the biweekly one. A full semi-monthly cheque is $3,250 and a full biweekly cheque is $3,000. The semi-monthly convention pays 6 ÷ 11 — 54.5% — of $3,250, which is $1,773, with each workday worth $295. The biweekly convention pays 8 ÷ 14 — 57.1% — of $3,000, which is $1,714, with each calendar day worth $214. The hourly equivalent divides $78,000 by 2,080 to get $37.50 and pays 48 hours, which is $1,800. Same salary, same dates, three defensible answers $86 apart, and the largest is the hourly method rather than the headline semi-monthly one. At 24% withholding the semi-monthly figure nets about $1,347 — before benefit premiums, which are not prorated. Against a full cheque you are short $1,477 this period.
Definitions
- Semi-monthly
- Paid twice a month on fixed dates — 24 cheques a year. Prorates on the WORKDAYS in the half-month, a divisor that shifts between 10, 11 and 12.
- Biweekly
- Paid every fortnight — 26 cheques a year, each smaller than a semi-monthly one on the same salary. Prorates on all 14 CALENDAR days, weekends included.
- Workday divisor
- The number of working days in the pay period, used as the denominator by a semi-monthly payroll. It is not constant, which is why the same absence costs different amounts in different months.
- Salary-basis test
- The requirement that an exempt employee receive a predetermined salary not subject to reduction for variations in work quantity. Improper deductions can destroy the exemption.
- Three-paycheck month
- The two months a year in which a biweekly schedule produces three paydays. Not extra money — the same annual salary arriving in 26 pieces rather than 24.
- Proration convention
- The arithmetic rule an employer's written policy applies to a partial period. No federal law specifies one, so different payroll systems produce different answers on the same dates.
Good to know
No federal rule, so the conventions collide
Most pay questions have a federal answer somewhere. This one does not. The FLSA sets a wage floor and an overtime rule for nonexempt workers and says nothing whatever about how a salaried employee's partial pay period should be computed, so the arithmetic falls to the employer's written policy — and policies differ because payroll systems ship with different defaults. Two conventions dominate and they disagree about the same start date. A SEMI-MONTHLY payroll divides the period's salary by the WORKDAYS in that half-month and multiplies by the workdays you were employed. A BIWEEKLY payroll divides by all 14 CALENDAR days in the period, weekends included, and multiplies by the calendar days you were employed. A third method, the hourly equivalent, divides the annual salary by 2,080 hours and pays the hours. On $78,000 with 6 of 11 workdays and 8 of 14 calendar days, the three produce $1,773, $1,714 and $1,800 — an $86 spread on the same salary and the same dates, with the hourly method paying the most and the biweekly method the least. None of them is wrong. What makes the spread worth knowing is that you cannot choose: the system your employer runs decides, and it decided before you arrived. The practical upshot is a single question rather than an argument. If the figure on your stub does not match your own arithmetic, ask which divisor payroll used. That resolves the great majority of these disputes in one exchange, and the page's annual-salary check exists as the second test — each method, run backwards, should return your actual salary, and if payroll's figure does not, the divisor is the place to look.
For an exempt employee there is a hard limit on all of this
Before applying any proration to an exempt salary, check whether it is permitted at all, because the answer is usually no and the consequence of getting it wrong falls on the employer. 29 C.F.R. 541.602(b)(1) permits a proportionate part of an exempt employee's salary in the FIRST and LAST week of employment — and nowhere else. That is the whole of the allowance for partial weeks at the start and end of a job. Docking an exempt salary for other partial weeks breaks the salary-basis test, and the salary-basis test is one of the two pillars the exemption stands on. Break it and the exemption can be lost, which makes every hour over 40 in the period payable at time and a half, potentially for everyone in the same job classification rather than just the employee who was docked. There are narrow permitted deductions beyond the first and last week: full-day absences for personal reasons, full-day absences for sickness under a bona fide plan, unpaid disciplinary suspensions of a full day for serious workplace-conduct violations, and offsets for jury or witness fees. Partial-day absences generally may not be deducted at all, with FMLA leave the significant exception. There is also a safe harbour: an employer with a clearly communicated policy prohibiting improper deductions, which reimburses employees and makes a good-faith commitment to comply in future, can avoid losing the exemption for an isolated or inadvertent deduction. The practical reading for an exempt employee looking at this page is simple. If the period in question is neither your first week nor your last, and you were employed and available throughout, the correct prorated figure may well be the entire cheque, and the arithmetic above is a description of what a payroll system did rather than what it was entitled to do.
24 against 26, and the divisor that will not sit still
The two common pay frequencies are not the same cheque at a different rhythm, and confusing them causes both budgeting errors and proration disputes. Semi-monthly pays 24 times a year on two fixed dates — $3,250 each on a $78,000 salary — so the dates are predictable and the period lengths are not. Biweekly pays 26 times at $3,000, so the period length is always exactly 14 days and the dates wander through the month. Biweekly therefore produces two months a year with three paydays, which feels like a windfall and is not: it is the same annual salary arriving in 26 pieces rather than 24, and a budget built on two cheques a month will be short in ten months and flush in two. The proration consequence is the quiet unfairness in the semi-monthly method. Its divisor is the workdays in the half-month, and that count is not a constant — a half-month can hold 10, 11 or 12 workdays depending on where the weekends fall. So one workday is worth $295 in an 11-workday period and $325 in a 10-workday one, on exactly the same salary. The same single day of unpaid leave costs different amounts in different halves of the same month, and a start date two days apart can produce a materially different first cheque. The biweekly method has the opposite property and the opposite complaint: 14 calendar days every single period, forever, which is admirably consistent and pays you for weekends you did not work. There is a defensible logic to both — the salary covers the whole period including its weekends, or the salary is compensation for the working days within it — which is precisely why no federal rule picks one, and why a page that computes only one of them would be quietly wrong for half its readers.
Why the short cheque is shorter than the arithmetic
A partial paycheck is almost always smaller than the proration on this page predicts, and the reason is that the deductions do not prorate with the gross. Health, dental and vision premiums, life cover, parking and most other fixed benefit deductions come out of a partial cheque in full — and some employers take a whole month's premium from a single mid-month cheque as a matter of course. A percentage-based 401(k) deferral does scale down, because it is a percentage; a flat-dollar deferral does not. Withholding scales, since it is computed on the pay, and on the default figures $1,773 of gross comes to about $1,347 net at a combined 24% before a single premium is applied. Put a full month of family health premiums against that and a first or last paycheck can land near zero, which is alarming without being wrong. Knowing it in advance is the whole benefit: a first cheque is not a reliable guide to what the job pays, and a last cheque is not a reliable guide to what is owed. If this is a LAST cheque, two further rules apply, both of them state law. Final paycheck timing has no federal rule at all: it ranges from immediately on discharge in California, through 72 hours, to the next regular payday, which is the most common arrangement, and California adds a waiting-time penalty of up to 30 days' wages where the employer is late. Accrued leave is separate again — no federal law requires a payout, roughly 19 to 26 states plus the District of Columbia do, and four states (California, Colorado, Montana and Nebraska) bar use-it-or-lose-it policies outright. A final cheque therefore usually carries a prorated period and an accrued-leave payout together, computed on different rules and often withheld at different rates.
Frequently asked questions
Which proration method is the correct one?
There is no federal rule at all. The FLSA sets a floor for nonexempt workers and says nothing about the arithmetic for a salaried partial period, so the employer's written policy governs and payroll systems ship with different defaults. All three methods on this page are defensible. On the default figures they give $1,773 semi-monthly on workdays, $1,714 biweekly on calendar days, and $1,800 on the hourly equivalent — $86 apart on the same salary and the same dates, with the hourly method paying most and the biweekly method least.
Payroll's number does not match mine. Who is wrong?
Possibly neither. Ask which divisor was used before assuming an error, because that single question resolves most of these disputes. A semi-monthly payroll divides the period's $3,250 by the 11 workdays in that half-month, making each worth $295. A biweekly payroll divides its $3,000 by all 14 calendar days, making each worth $214. The page also reports the annual salary each method implies as a sanity check — it should come back to your salary, and if payroll's does not, the divisor is where to look.
Why is a biweekly cheque smaller than a semi-monthly one on the same salary?
Because it arrives 26 times a year rather than 24. On $78,000, semi-monthly pays $3,250 twice a month on fixed dates while biweekly pays $3,000 every fortnight. Biweekly also produces two months a year with three paydays, which feels like a bonus and is not — it is the same annual salary arriving in 26 pieces. A budget built on two cheques a month breaks in those months and in the opposite direction in every other one.
I am exempt. Can my employer dock my salary for a partial week?
Very rarely, and getting it wrong is expensive for the employer. 29 C.F.R. 541.602(b)(1) permits a proportionate part of the salary in the FIRST and LAST week of employment, and nowhere else. Docking an exempt salary for other partial weeks breaks the salary-basis test, and losing the exemption makes every hour over 40 in the period payable at time and a half — for that employee and potentially for everyone in the same classification. Full-day absences for personal reasons may be deducted; partial-day absences generally may not, except under the FMLA.
Why was my first paycheck so much smaller than the proration suggested?
Because the deductions are not prorated with the gross. Health, dental and vision premiums and most fixed benefit deductions come out of a partial cheque in full — some employers take a whole month's premium from a single mid-month cheque — while a percentage-based 401(k) deferral does scale down. On the default figures $1,773 of gross withholds to about $1,347 at 24% BEFORE any premium comes out, and a full month of premiums against half a month of pay is how a first or last cheque ends up at almost nothing.
Do holidays count as workdays in the divisor?
That is set by the employer's policy, and it is worth confirming rather than assuming, because it moves the answer. A paid company holiday inside the period is normally counted as a workday both in the divisor and in the days you were paid for, which leaves the fraction unchanged. An unpaid closure is not. The page lets you enter both figures directly for exactly this reason — the divisor and the numerator are separate fields, so you can match whatever convention your employer actually uses.
When must my final paycheck arrive?
Entirely state law — there is no federal rule. It ranges from immediately on discharge in California, through 72 hours, to the next regular payday, which is the most common. California adds a waiting-time penalty of up to 30 days' wages where the employer is late. Accrued leave is a separate question again: no federal law requires a payout, roughly 19 to 26 states plus DC do, and four — California, Colorado, Montana and Nebraska — bar use-it-or-lose-it policies outright.
Why does one day of unpaid leave cost different amounts in different months?
Because the semi-monthly workday divisor moves. A half-month can hold 10, 11 or 12 workdays depending on where the weekends fall, so each workday is worth $295 in an 11-day period and $325 in a 10-day one on the same $78,000 salary. The biweekly method has the opposite property — always 14 calendar days, forever, which is more consistent but pays you for weekends you never worked.