Precision Utility
Pro Rata Salary
Calculator
Standard FT Hours
37.5
Working Days / Year
260
Work out your pro rata salary when switching to part-time hours. Enter the full-time equivalent salary and both the standard and your actual weekly hours. The calculator instantly shows your adjusted annual, monthly, weekly, daily and hourly pay so you know exactly what to expect on your payslip.
Hours & Salary
Pro Rata Annual Salary
£21,000
Monthly
£1,750
Weekly
£404
Daily
£80.77
Hourly
£17.95
Full-Time Salary
£35,000
Your Hours
22.5 of 37.5 hrs
% of Full-Time
60.0%
Hourly Rate
£17.95 / hr
How the pro rata calculator works
Enter the full-time equivalent (FTE) annual salary — that is the amount you would earn if you worked the standard full-time hours. Then set the full-time hours per week (usually 37.5 or 40 in the UK) and your actual contracted hours per week.
The calculator divides your hours by the full-time hours to get your pro rata fraction, then multiplies this by the annual salary. From that single figure it derives your monthly, weekly, daily and hourly pay so you can see the full picture at a glance.
Results update automatically whenever you move a slider or change an input value. There is no need to press the button unless you prefer to — the calculation runs instantly as you type or slide.
Understanding pro rata pay in the UK
In UK employment, "pro rata" literally means "in proportion". It is most commonly used when a job is advertised with a full-time equivalent salary but offered on a part-time basis. The actual pay you receive is proportional to the hours you work.
For example, a role advertised at £30,000 FTE with standard hours of 37.5 per week pays someone working 22.5 hours a pro rata salary of £18,000 per year. The formula is straightforward:
- Pro rata salary = (your hours ÷ full-time hours) × full-time salary
- Monthly pay = pro rata salary ÷ 12
- Weekly pay = pro rata salary ÷ 52
- Daily pay = pro rata salary ÷ 260 (working days per year)
- Hourly rate = pro rata salary ÷ (your hours × 52)
Part-time workers have the same legal rights as full-time employees under the Part-Time Workers (Prevention of Less Favourable Treatment) Regulations 2000. This means benefits, bonuses and holiday entitlement should normally be calculated on a pro rata basis.
Pro rata holiday entitlement
UK workers are entitled to a minimum of 5.6 weeks of paid annual leave, which equals 28 days for someone working 5 days a week. Part-time workers receive this on a pro rata basis. If you work 3 days a week, your statutory entitlement is 3 × 5.6 = 16.8 days per year.
Many employers offer more than the statutory minimum. Whatever the total entitlement, it is scaled by the same fraction used for your salary — your contracted hours divided by the full-time hours.
Frequently asked questions
What does pro rata mean?
Pro rata means "in proportion". When applied to salary, it refers to the amount you earn based on the fraction of full-time hours you actually work. A pro rata salary adjusts a full-time equivalent wage to reflect your part-time hours.
How is pro rata salary calculated?
Pro rata salary is calculated by dividing your actual weekly hours by the full-time weekly hours, then multiplying by the full-time annual salary. For example, if the full-time salary is £30,000 for 37.5 hours per week and you work 22.5 hours, your pro rata salary is (22.5 ÷ 37.5) × £30,000 = £18,000.
Does pro rata affect my pension contributions?
Yes. Your pension contributions are typically based on your actual (pro rata) earnings, not the full-time equivalent salary. Both your contribution and your employer's contribution are calculated on the salary you actually receive. This means part-time workers contribute less in absolute terms but at the same percentage rate.
How does pro rata affect holiday entitlement?
Part-time workers are entitled to a pro rata share of the statutory 28 days (5.6 weeks) holiday. If you work 3 days a week instead of 5, you receive 3 ÷ 5 × 28 = 16.8 days of paid holiday per year. Your employer may round this up to the nearest half or whole day.
How do you calculate pro rata pay for someone who starts mid-year?
For a mid-year starter, divide the annual salary by 365 (or 366 in a leap year) to get the daily rate, then multiply by the number of remaining calendar days in the year. Alternatively, divide by 12 and multiply by the number of complete months plus a fraction for any partial month.
Is a bonus paid pro rata for part-time workers?
It depends on your employment contract. Many employers pay bonuses on a pro rata basis for part-time staff, meaning you receive the same proportion as your working hours compared to full-time. However, some bonuses are paid equally regardless of hours — always check your contract or speak to your employer.