How is a pro-rata salary calculated for part-year or part-time workers?

Full answer

Pro-rata means "in proportion." It is used to calculate fair pay when an employee works fewer hours than full-time, or joins or leaves partway through the year. **Part-time pro-rata calculation** Formula: Pro-rata salary = (FTE annual salary ÷ full-time weekly hours) x contracted weekly hours Worked example: Full-time salary: £35,000/year (based on 37.5 hours/week) Employee contracted: 25 hours/week Pro-rata salary = (£35,000 ÷ 37.5) x 25 = £933.33 x 25 = £23,333/year Hourly rate check: £35,000 ÷ (37.5 x 52) = £17.95/hour 25 hours x 52 weeks x £17.95 = £23,335 (rounding difference) **Part-year pro-rata calculation** Formula: Pay = (Annual salary ÷ 52) x weeks worked Worked example: Teacher joining on 1 September 2026, salary £42,000/year Academic year runs September to July = approximately 39 weeks Pay for that year = (£42,000 ÷ 52) x 39 = £807.69 x 39 = £31,500 **Starting or leaving mid-month** Employers commonly use calendar day method: Formula: (Annual salary ÷ 365) x days employed in the period Example: Employee joins 15 April 2026, salary £30,000 Days from 15 April to 5 April 2027 (tax year end): 355 days Pay: (£30,000 ÷ 365) x 355 = £29,178 **National Living Wage check** Pro-rata pay must still comply with minimum wage law. The hourly rate after calculating pro-rata pay must be at least the NLW (£12.21/hour from April 2025, estimated £12.60 from April 2026). **Pension contributions** Auto-enrolment qualifying earnings (£6,240 lower threshold and £50,270 upper threshold) apply to the actual pro-rata earnings, not the FTE salary. A part-time worker earning £8,000/year contributes on £8,000 - £6,240 = £1,760. **Holiday entitlement** Statutory holiday (5.6 weeks) is also pro-rated. A 3-day/week worker gets 5.6 x 3 = 16.8 days per year.