Calculate your proportional part-time earnings, weekly rates, and equivalent hourly pay from a full-time annual salary.
How to Calculate Pro Rata Salary
When an employment vacancy is advertised with a "pro rata" salary, the stated figure represents what a full-time worker receives. If you contract to work part-time hours, your actual gross pay is scaled down in direct proportion to your hours.
The arithmetic formula to derive pro rata salary is:
Pro Rata Salary = Full-Time Annual Salary × (Part-Time Hours Worked ÷ Standard Full-Time Hours)
From the annual prorated figure, supporting compensation periods are calculated:
Monthly Rate: Annual Pro Rata Salary ÷ 12
Weekly Rate: Annual Pro Rata Salary ÷ 52
Hourly Rate: Weekly Rate ÷ Hours Worked Per Week
Worked Salary Calculation Examples
Example 1: 30 Hours of 37.5h Full-Time (£30,000)
Standard UK full-time week is 37.5 hours. An employee contracts for 30 hours per week:
• FTE Share: 30 ÷ 37.5 = 80.00%
• Annual Salary: £30,000 × 0.80 = £24,000.00
• Monthly Pay: £24,000 ÷ 12 = £2,000.00
• Weekly Pay: £24,000 ÷ 52 = £461.54
• Hourly Rate: £461.54 ÷ 30 = £15.38/hr
Example 2: 3 of 5 Days Worked (£40,000)
Full-time role of 5 days per week. An employee works 3 days each week:
• FTE Share: 3 ÷ 5 = 60.00%
• Annual Salary: £40,000 × 0.60 = £24,000.00
• Monthly Pay: £24,000 ÷ 12 = £2,000.00
• Weekly Pay: £24,000 ÷ 52 = £461.54
Got Questions?
Frequently Asked Questions (Salary)
Everything you need to know about calculating pro rata wages, FTE fractions, and part-time rates.
What is Full-Time Equivalent (FTE) and how is it calculated?
Full-Time Equivalent (FTE) represents the proportion of a full-time workload an employee works. It is calculated by dividing your scheduled weekly hours by the employer's standard full-time weekly hours. For example, 30 hours per week divided by a 40-hour full-time baseline equals 0.75 FTE (75%).
What is the formula to calculate pro rata salary from an annual full-time rate?
The standard pro rata salary formula is: Pro Rata Salary = (Part-Time Hours ÷ Full-Time Hours) × Full-Time Annual Salary. For example, if a position offers £40,000 full-time for 37.5 hours and you work 22.5 hours, your pro rata annual salary is (22.5 ÷ 37.5) × £40,000 = 0.60 × £40,000 = £24,000 gross per year.
How does part-year salary estimation work when starting or leaving mid-year?
When an employee works only part of a calendar or tax year, gross earnings are prorated by dividing the inclusive calendar days employed by the total days in that specific calendar year (365 days, or 366 in a leap year). This provides a reliable calendar-day estimate for annual financial planning.
Does a pro rata salary affect pensions, bonuses, and employee benefits?
Statutory benefits, employer pension contributions, and accrued sick leave typically scale directly with your pro rata earnings. Discretionary performance bonuses, life insurance, and healthcare perks vary based on individual employment contracts—some employers prorate bonuses, while others assess them against target criteria.
How do you convert an annual pro rata salary into monthly and weekly pay?
Divide your annual pro rata gross salary by 12 for gross monthly pay, by 52 for weekly pay, or by 26 for bi-weekly/fortnightly pay. For instance, a £24,000 pro rata annual salary equals £2,000 gross per month, £923.08 bi-weekly, or £461.54 weekly.
Should I calculate pro rata salary using hours worked or days worked?
Both produce identical mathematical results when daily hours are consistent. If full-time is 5 days (40 hours) and you work 3 days (24 hours), both 3 ÷ 5 and 24 ÷ 40 yield an FTE of 0.60 (60%). If your daily hours vary, calculating by total weekly hours offers greater accuracy.