Pro Rata Salary Calculator
Calculate your pro rata salary based on full-time equivalent
About This Tool
The Pro Rata Salary Calculator helps part-time workers in the UK quickly determine their proportional salary based on their working hours. Whether you're transitioning from full-time to part-time work, negotiating a new position, or simply want to understand your earnings better, this free tool provides instant, accurate calculations.
Pro rata means "in proportion" - your salary is calculated as a proportion of what a full-time employee in the same role would earn. This calculator takes into account UK employment standards and helps you understand exactly what you should be paid.
How It Works
How to Use This Calculator
Using our pro rata salary calculator is simple:
- Enter your full-time equivalent salary - This is the annual salary for the full-time version of your role. You can find this in your job advertisement or contract.
- Enter full-time hours - The standard weekly hours for a full-time position in your organisation. This is typically 37.5 or 40 hours per week in the UK.
- Enter your actual hours - The number of hours you work (or will work) per week in your part-time role.
- Click Calculate - Get your pro rata annual salary instantly, along with monthly and hourly breakdowns.
The calculator automatically handles the maths, so you don't need to worry about complex formulas.
Formula
Pro Rata Salary Formula
The calculation uses this straightforward formula:
Pro Rata Salary = Full-Time Salary x (Your Hours / Full-Time Hours)
Or expressed another way:
Pro Rata Salary = (Full-Time Salary / Full-Time Hours) x Your Hours
This gives you the same hourly rate as a full-time employee, just for fewer hours.
Examples
Examples
Example 1: 3 Days Per Week
- Full-time salary: £30,000
- Full-time hours: 37.5 hours/week (5 days)
- Your hours: 22.5 hours/week (3 days)
- Pro Rata Salary = £30,000 x (22.5 / 37.5) = £18,000
Example 2: 4 Days Per Week
- Full-time salary: £45,000
- Full-time hours: 40 hours/week
- Your hours: 32 hours/week (4 days)
- Pro Rata Salary = £45,000 x (32 / 40) = £36,000
Example 3: Reduced Hours
- Full-time salary: £28,000
- Full-time hours: 37.5 hours/week
- Your hours: 30 hours/week
- Pro Rata Salary = £28,000 x (30 / 37.5) = £22,400
Frequently Asked Questions
How do I calculate a pro rata salary?
Pro rata salary = Full-Time Salary × (Actual Hours / Full-Time Hours). If the full-time salary is £40,000 for 37.5 hours/week and you work 22.5 hours: £40,000 × (22.5/37.5) = £24,000 per year.
What does pro rata mean for a job listing?
When a job ad states "£35,000 pro rata," it means £35,000 is the full-time equivalent salary. Your actual pay depends on your contracted hours. Working 3 days out of 5: actual salary = £35,000 × 0.6 = £21,000.
How do I calculate pro rata salary for a mid-month start?
Monthly pro rata = Annual Salary / 12 × (Working Days in Month / Total Working Days in Month). Starting on the 15th of a month with 22 working days, with 10 remaining: one month pay × (10/22).
Does pro rata salary affect pension and benefits?
Pension contributions are typically based on actual pro rata salary. Some benefits like health insurance may be provided at the same level as full-time. Others like bonus and holiday are usually pro-rated proportionally.
How do I convert hourly rate to pro rata annual salary?
Annual salary = Hourly Rate × Hours per Week × 52. For £15/hour at 25 hours/week: £15 × 25 × 52 = £19,500. The full-time equivalent at 37.5 hours would be £29,250. The calculator converts between all formats.
Disclaimer
Disclaimer: This calculator provides estimates based on the information you enter and is intended for general guidance only. It does not constitute professional employment or financial advice. For specific queries about your employment rights, salary calculations, or contractual terms, please consult your employer, HR department, or contact ACAS (Advisory, Conciliation and Arbitration Service) for free, impartial advice. Employment law and regulations may change; always verify current rates and rules with official sources.
💡 Tips
Tips
- Check your contract - Always verify the full-time equivalent salary and standard hours with your employer
- Consider benefits - Some benefits like pension contributions may also be calculated pro rata
- Tax implications - Your tax bracket is based on your actual earnings, not the full-time equivalent
- Holiday entitlement - Your annual leave is also calculated pro rata (use our Holiday Calculator)
- Overtime rates - Understand how overtime is calculated if you work additional hours