Pro-Rata Salary Calculator — Part-Time Pay From Full-Time

The calculation in one line

Pro-rata salary = full-time salary × (hours worked ÷ full-time hours). A role paying 60,000 for a 40-hour week, worked at 24 hours, pays 60,000 × (24 ÷ 40) = 36,000 a year. That is 3,000 a month or 692.31 a week. The Latin phrase pro rata means in proportion, and proportion is the whole mechanism: pay scales with hours, and everything derived from pay — monthly figures, time-off accrual, often pension contributions — scales with the same ratio. The share-of-full-time row makes the ratio explicit; in this example the role is a 60% position.

The hourly rate does not change

A common misreading of part-time pay is that fewer hours mean a lower rate. Pro-rating holds the hourly rate fixed and varies only the quantity of hours. The 60,000 role over 40 hours and 52 weeks is 28.85 an hour, and the 24-hour version of the job pays exactly the same 28.85 — for fewer hours. If a part-time offer implies a lower hourly rate than the full-time equivalent, that is not pro-rating; it is a different rate, and the calculator makes the comparison visible by showing the rate the proportional arithmetic produces. The days-versus-hours framing also matters less than it seems: three days of a five-day week and 24 hours of a 40-hour week are the same 60% ratio, so either counting method lands on the same salary.

Paid time off scales the same way

A full-time allowance of 25 days pro-rated to 60% becomes 15 days. The proportional method is the standard approach across most employment systems, though the details — whether public holidays are inside or outside the allowance, how part-week patterns round, what minimum statutory floors apply — differ by country and by contract. The calculator applies the plain ratio to whatever full-time allowance is entered, which is the arithmetic backbone every local variation builds on. For patterns where the worked days vary week to week, annual-hours contracts typically pro-rate on hours rather than days, which the hours-based inputs here already handle.

Where pro-rata arithmetic shows up

Reduced-hours arrangements are widespread — across OECD countries, part-time roles account for a substantial share of employment, with rates above 30% in some labour markets — and the same proportional calculation covers most of them. A job share splits one full-time role across two people, each paid their fraction. A phased return after leave steps the ratio up over several months, with pay following each step. A compressed week is the notable exception: working 40 hours across four longer days is full-time hours in a different shape, so no pro-rating applies at all. Term-time contracts and roles with unpaid weeks pro-rate on weeks per year as well as hours per week — a second ratio this calculator does not model, since it treats the year as fully worked.

Worked example at a different scale

The ratio machinery is scale-independent. A 52,500 full-time salary at 40 hours, worked three days (24 hours), gives 52,500 × 0.6 = 31,500 — an hourly rate of 25.24 unchanged from the full-time role. Doubling the salary doubles every output; halving the hours halves the pay and the time off but leaves the rate untouched. That separability is useful in negotiations over hours, because it isolates the one number that actually changes.

What sits outside the ratio

The calculator handles gross pay. Take-home pay does not scale in the same clean proportion, because tax systems are progressive in most countries — a 60% salary usually keeps more than 60% of the full-time take-home, since a larger share of it falls into lower tax bands or below tax-free thresholds. Benefits with fixed costs, such as flat-rate insurance premiums or per-employee allowances, also break the proportion in either direction. And salary benchmarks for a role are typically quoted full-time, so the Hourly Rate vs Salary Calculator and the Part-Time vs Full-Time Calculator pick up the comparison questions this ratio deliberately leaves alone — including the value of benefits packages across working patterns.