Pro-Rata Salary Calculator

A pro-rata salary scales a full-time equivalent figure down to reflect actually working fewer hours, fewer weeks of the year, or both — and genuinely getting this right means accounting for whichever of these actually applies to your specific role, not just the hours reduction most people think of first. This calculator works out your pro-rata salary and realistic take-home pay from your full-time equivalent salary, hours and weeks worked.

The Two Ratios That Actually Determine Pro-Rata Pay

Pro-rata pay genuinely depends on two separate ratios multiplied together, not just one: your actual hours as a proportion of full-time hours, and your actual weeks worked as a proportion of a standard 52-week year. Someone working reduced hours across a full 52-week year only needs the hours ratio applied. Someone working full-time hours but for fewer weeks of the year — a genuinely different, distinct scenario — needs the weeks ratio applied instead. And someone working both reduced hours and reduced weeks needs both ratios combined, since either one alone would overstate the real pro-rata figure.

This calculator applies both ratios together specifically because relying on only the hours ratio, the more commonly understood of the two, would genuinely overstate pay for anyone on a reduced-weeks pattern — entering your actual weeks worked, not just leaving it at the default full year, is essential for an accurate result if your role does not run across all 52 weeks.

Why Term-Time-Only Work Needs a Second Calculation

Term-time-only contracts — common for school support staff, some catering and education roles — typically involve working full, standard hours each week, but only across roughly 38–39 weeks of the year rather than the full 52. This is a genuinely different pattern from simply working part-time hours, and it is easy to underestimate how much it actually reduces the annual salary if only the hours ratio is considered: someone on full-time hours for 39 weeks a year is working roughly 75% of a standard working year, even though their weekly hours look identical to a full-time colleague’s.

This is worth being genuinely clear about specifically when comparing a term-time-only role against a standard, full-year role quoting a similar-looking hourly rate or FTE salary — the weekly experience of the job may look identical, but the actual annual income is genuinely, meaningfully lower once the reduced number of working weeks is properly accounted for.

Seeing Both Ratios Applied Together

A £32,000 FTE role, worked at full standard hours but for 39 weeks a year rather than 52, produces a pro-rata gross salary of £24,000 — the hours ratio does not reduce it at all here, since the hours themselves are full-time, but the weeks ratio (39/52) reduces it to 75% of the FTE figure. After standard 2026/27 tax and NI, that leaves take-home pay of roughly £20,800 a year, around £1,733 a month — a considerably more concrete number than the headline £32,000 FTE figure alone would suggest.

The FTE Salary Isn’t Always What It Looks Like

The “full-time equivalent” salary quoted for a role is a reference point — what the role would pay at standard full-time hours across a full 52-week year — not necessarily what anyone in that specific role is actually being paid, since almost any combination of reduced hours or reduced weeks scales it down from there. This distinction matters specifically when comparing job offers: two roles both quoting a “£32,000 FTE” salary can produce genuinely different actual pay if one is 30 hours a week across 52 weeks and the other is full-time hours across 39 weeks, even though the headline FTE figure looks identical on paper.

Turning Pro-Rata Into a Real Take-Home Figure

A pro-rata gross salary is not the number that actually lands in your bank account — this calculator applies standard 2026/27 Income Tax and National Insurance to the pro-rata figure specifically, since tax and NI are calculated on your actual annual income, not on the full-time equivalent salary you would earn if working full hours and weeks. This is worth checking directly rather than assuming your take-home simply scales down in the same proportion as your gross pay, since your Personal Allowance and tax bands apply to your real, pro-rata income throughout — and because tax is progressive, a lower pro-rata income can sometimes mean proportionally less of it is lost to tax than the equivalent full-time salary would suggest. Our Take-Home Pay Calculator is useful for a more detailed breakdown of deductions once you know your pro-rata gross figure, and our Hourly Wage Tax Calculator is worth checking if your pay is structured around an hourly rate rather than an annual FTE salary.

Frequently Asked Questions

Important Information

This calculator provides an estimate based on standard 2026/27 tax and NI rates for general information purposes only and does not constitute tax or employment advice. Actual pay depends on your specific contract terms. See our Disclaimer for further information.