How to Work Out Full-time Salary From Pro Rata
Clear explanation with practical examples for UK workers
Working Out Full-Time Salary from Pro Rata
If you know your pro rata (part-time) salary and want to find the full-time equivalent, the calculation is a simple reversal of the standard pro rata formula. Divide your actual salary by your FTE ratio to reveal what the role pays at full-time hours.
Example: You earn £18,000 working 22.5 hours where full-time is 37.5. FTE ratio = 22.5 ÷ 37.5 = 0.6. Full-time salary = £18,000 ÷ 0.6 = £30,000.
Reverse Pro Rata Worked Examples
| Your Salary | Your Hours | FT Hours | FTE | Full-Time Salary |
|---|---|---|---|---|
| £12,000 | 15 | 37.5 | 0.40 | £30,000 |
| £16,000 | 25 | 37.5 | 0.67 | £24,000 |
| £22,400 | 28 | 35 | 0.80 | £28,000 |
| £20,000 | 20 | 40 | 0.50 | £40,000 |
Why You Might Need the FTE Salary
Knowing the full-time equivalent salary is essential for: comparing job offers at different hours, checking your pay grade against published scales, calculating what a full-time return would pay, negotiating a pay rise (discussions should reference the FTE figure), and verifying pension statements (which sometimes show FTE salary).
Use our FTE calculator to convert between hours and FTE ratios. For the forward calculation (FTE salary to pro rata), use the pro rata calculator. To check your salary is correct against published pay scales, try the salary checker.
Quick Summary: How to Work Out Full-time Salary From Pro Rata
If you're short on time, here's what you need to know about how to work out full-time salary from pro rata:
- What it means: How to Work Out Full-time Salary From Pro Rata involves calculating pay or entitlement proportionally based on the ratio of hours or time worked versus the full-time equivalent.
- The formula: Full-Time Amount × (Your Hours ÷ Full-Time Hours) = Your Pro Rata Amount
- Who needs it: Part-time workers, term-time staff, teachers, job-sharers, and anyone on reduced hours.
- UK law: Under the Part-time Workers Regulations 2000, part-time employees have the right to be treated no less favourably than comparable full-time workers.
Worked Example: How to Work Out Full-time Salary From Pro Rata
Let's work through a practical example of how to work out full-time salary from pro rata. A marketing coordinator role advertises a full-time salary of £28,000 for 37.5 hours per week. You're offered the position at 25 hours per week.
Step 1 — Find your FTE ratio: 25 ÷ 37.5 = 0.667 (66.7%)
Step 2 — Calculate pro rata salary: £28,000 × 0.667 = £18,667 per year
Step 3 — Monthly breakdown: £18,667 ÷ 12 = £1,556 gross per month
Step 4 — Holiday entitlement: 28 days × 0.667 = 18.7 days pro rata
After income tax and NI (2025/26 rates), your monthly take-home would be approximately £1,377. Use our pro rata calculator above to check your own figures.
Tips for How to Work Out Full-time Salary From Pro Rata
- Always use gross salary: Enter the salary before tax and deductions — the calculator works with gross figures.
- Check your contract: Your employment contract should state your full-time equivalent hours. Common UK standards are 35, 37, 37.5, and 40 hours per week.
- Know your rights: Under the Part-time Workers Regulations 2000, part-time employees must receive the same hourly rate, holiday entitlement (pro rata), and benefits as full-time colleagues.
- Tax personal allowance: For 2025/26, the first £12,570 of earnings is tax-free. If your pro rata salary falls below this, you pay no income tax at all.
- National Insurance: Employee NI is 8% on earnings between £12,570 and £50,270 (2025/26 rates). Check HMRC NI rates for the latest figures.
Pro Rata Holiday Entitlement
Under the Working Time Regulations 1998, all UK workers are entitled to a minimum of 5.6 weeks' paid holiday per year (28 days for full-time). If you work part-time, your entitlement is calculated pro rata based on your actual hours or days worked.
| Days Worked/Week | FTE Ratio | Statutory Days/Year | Bank Holidays (pro rata) |
|---|---|---|---|
| 5 days (full-time) | 1.0 | 28 days | 8 days |
| 4 days/week | 0.8 | 22.4 days | 6.4 days |
| 3 days/week | 0.6 | 16.8 days | 4.8 days |
| 2.5 days/week | 0.5 | 14 days | 4 days |
| 2 days/week | 0.4 | 11.2 days | 3.2 days |
Holiday entitlement is always rounded up — never down — when the result is not a whole number, per ACAS guidance on holiday entitlement. Bank holidays may be included in or added on top of your statutory 28 days, depending on your contract.
All calculations on this page follow ACAS pro rata pay guidelines and are consistent with the UK Employment Rights Act 1996. Tax figures use HMRC 2025/26 rates. The April 2025 National Living Wage of £12.21/hour is applied where relevant.
Further Reading
For more help with how to work out full-time salary from pro rata, explore our free UK tools. You may also find these useful: term-time salary calculator, overtime calculator, holiday pay guide.
Last updated: February 2026. Verified against HMRC 2025/26 tax rates and April 2025 National Living Wage (£12.21/hour).
Frequently Asked Questions
Pro rata means "in proportion." In employment, it refers to adjusting a full-time salary proportionally based on the number of hours, days, or weeks actually worked compared to a full-time equivalent role.
Divide the full-time salary by full-time hours, then multiply by your actual hours. For example: £30,000 ÷ 37.5 hours × 25 hours = £20,000 pro rata.
Pro rata salary is usually calculated before holiday pay. Your holiday entitlement is also pro-rated — part-time workers get 5.6 weeks holiday pro rata, calculated proportionally to hours worked.
Not exactly. Pro rata is the method used to calculate part-time salary. It ensures part-time workers receive the proportional equivalent of the full-time rate, maintaining fairness under UK employment law.