How to calculate a pro-rata salary for a 3-day or 4-day week
Divide the full-time equivalent salary by the full-time weekly hours, then multiply by your weekly hours. Compare like with like, using paid hours for both schedules. Days are a shortcut when each day is the same length.
Examples using £40,000 full-time equivalent
- Three equal days out of five gives 60% of full-time pay, or £24,000 gross a year and £2,000 per month on average.
- Four equal days out of five gives 80%, or £32,000 gross a year and about £2,666.67 per month.
When four days still means full-time pay
If you compress the same full-time hours into four longer days, the hours ratio is still 100%. Ask whether the advertised salary is full-time equivalent or the actual pay for the proposed hours. Use the pro-rata salary calculator first, then enter the result into the take-home pay calculator to estimate deductions.
Official guidance · Read the GOV.UK guidance