Pro-Rata Salary Calculator UK 2026/27: Part-Time Pay

Pro-rata means “in proportion”. A pro-rata salary is the amount paid to a part-time employee calculated proportionally from the equivalent full-time salary (FTE), based on the actual hours or days worked compared to a standard full-time contract (typically 37.5 or 40 hours per week).

The formula is: Pro-Rata Salary = (Actual Weekly Hours ÷ Full-Time Hours) × Full-Time Annual Salary. For example, if a full-time role pays £30,000 for 37.5 hours and you work 22.5 hours, your pro-rata salary is (22.5 ÷ 37.5) × £30,000 = 60% × £30,000 = £18,000 per year (£1,500 per month).

Multiply your hourly rate by your weekly hours, and then multiply by the number of weeks worked per year (typically 52 weeks for all-year contracts, or 39–44 weeks for term-time roles). For example: £15.50 per hour × 20 hours per week × 52 weeks = £16,120 per year.

Statutory annual leave for full-time workers is 5.6 weeks (28 days for a 5-day week). Part-time workers receive the exact same 5.6 weeks pro-rated to their working pattern: multiply 5.6 by your weekly working days (e.g., 3 days/week × 5.6 = 16.8 days) or by your weekly hours (e.g., 22.5 hours × 5.6 = 126 hours of leave per year).

Yes. Under the Part-time Workers (Prevention of Less Favourable Treatment) Regulations 2000, part-time workers are entitled to a pro-rata share of bank holidays, regardless of whether their scheduled working days fall on a Monday. Many employers add pro-rata bank holiday hours to the overall annual leave allowance to ensure fair treatment.

Employers must auto-enrol workers earning over the £10,000 annual earnings trigger (£833/month or £192/week). If your pro-rata salary falls below £10,000, your employer is not legally required to auto-enrol you, but you retain the legal right to opt into the workplace pension scheme and receive employer contributions if you earn above £6,240.

Yes. UK law requires that bonuses, staff discounts, training opportunities, and redundancy pay are provided on a pro-rata basis to part-time staff compared to full-time equivalents, unless an employer can objectively justify different treatment on business grounds.

FTE (Full-Time Equivalent) salary represents what the role would pay if worked on a full-time contract (e.g., 37.5 or 40 hours per week). The pro-rata salary is your actual gross contractual pay based on your agreed part-time hours. Job adverts often quote the FTE salary; your actual pay packet will be the pro-rata amount.

Term-time salaries pro-rate pay across the weeks worked (typically 39 school weeks) plus pro-rata paid statutory holiday entitlement (typically 5 to 6 weeks), spread evenly across 12 monthly pay packets. The formula is: Hourly Rate × Weekly Hours × (Working Weeks + Holiday Weeks) ÷ 12.

Yes. Income Tax and Class 1 National Insurance are calculated on your actual pro-rata earnings, not the full-time FTE salary. Because everyone gets a personal allowance of £12,570 before paying Income Tax and the same £12,570 NI Primary Threshold, a lower pro-rata salary incurs significantly lower effective tax rates.

Divide your actual days worked per week by the standard full-time working days (usually 5), then multiply by the full-time annual salary. For example, working 3 days on a 5-day £28,000 full-time role gives (3 ÷ 5) × £28,000 = 60% × £28,000 = £16,800 per year.

No. The Part-time Workers Regulations 2000 make it unlawful to treat part-time workers less favourably than comparable full-time colleagues regarding pay rates, holiday entitlement, career progression, or contractual benefits, unless the employer has an objective, non-discriminatory business justification.