How to Calculate Salary Pro Rata
To calculate salary pro rata, start with the full-time salary and scale it by the proportion of full-time hours you actually work. The usual method is: full-time salary divided by full-time weekly hours, multiplied by your weekly hours. A £30,000 salary for a 37.5-hour week becomes £24,000 for a 30-hour week.
Days matter as well as hours. If you work fewer days but the same hours per day, the same formula still works, because it is the total weekly hours that count. Where working patterns vary by week, use the average weekly hours over a representative period, and check whether your contract defines pro rata by hours, days or working weeks.
Holiday entitlement is pro rated the same way. A full-time allowance of 28 days including bank holidays becomes 22.4 days for someone working four days out of five. Employers usually round part-days, and the rounding rule should be in your contract or staff handbook.
- Pro rata salary = full-time salary ÷ full-time hours × your hours.
- Use average weekly hours where patterns vary.
- Holiday is pro rated the same way; check the rounding rule.
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