Free Pro Rata Holiday Calculator
Calculate annual leave entitlement for part-time staff, joiners, and leavers. Enter your details below and click calculate.
What is a pro rata holiday calculation?
A pro rata holiday calculation works out annual leave entitlement in proportion to the time an employee actually works. It is commonly used when someone works part-time, starts mid-year, leaves before the end of the leave year, or changes working patterns.
In short, pro rata ensures holiday entitlement is fair and proportional rather than giving every employee the same fixed number of days.
The basic formula
Step 1: Adjust for part-time working pattern
If full-time entitlement is based on a 5-day week, and the employee works fewer days, use:
Part-time full-year entitlement = Full-time entitlement × (Employee days per week ÷ Full-time days per week)
Example: 28 days × (3 ÷ 5) = 16.8 days.
Step 2: Adjust for part-year employment
If the employee only works part of the leave year (for example, joins in June), multiply by the fraction of the leave year worked:
Pro rata entitlement = Part-time full-year entitlement × (Days employed in leave year ÷ Total days in leave year)
Why this matters for employers and employees
- Prevents over-allocation or under-allocation of paid leave.
- Supports compliance with employment law and internal policy.
- Improves payroll accuracy when paying holiday on termination.
- Makes leave balances transparent for HR teams and staff.
How to use this calculator correctly
1) Enter contractual values, not assumptions
Use your contract leave entitlement and normal working week definitions. If your company counts public holidays separately, only enter the contractual annual leave figure in days.
2) Use the actual leave year dates
Some organisations run leave years from January to December, while others use April to March or employee anniversary dates. Always use your real leave-year boundaries.
3) Include joiner/leaver dates
Joining and leaving dates can materially affect final entitlement, especially in shorter employment periods.
4) Apply the right rounding rule
Rounding practices vary by policy. Some businesses round up to the nearest half-day; others keep exact decimals. The calculator lets you apply a rounding method for planning and payroll consistency.
Common mistakes to avoid
- Using months instead of exact dates (can create small but important errors).
- Forgetting leap years when calculating annual proportions manually.
- Ignoring changes in work pattern during the year.
- Mixing days and hours without a consistent conversion method.
- Assuming bank holidays are always included in entitlement.
Days vs hours: which should you use?
Many employers calculate entitlement in days for fixed-day workers and in hours for variable schedules. This tool outputs both, using your entered hours-per-day value.
If shifts vary significantly, an hourly accrual model is often more precise.
FAQ
Does this include bank holidays?
It depends on what number you enter as full-time entitlement. If your contract says “28 days including bank holidays,” then yes, those are already included in the figure.
Can this calculator be used for leavers?
Yes. Add an employment end date and an as-of date to see how much leave was earned up to departure.
Is rounded entitlement legally required?
Rules vary by jurisdiction and policy. This tool gives exact and rounded outputs for practical use, but final treatment should follow your contract, handbook, and local law.
Final note
A pro rata holiday calculator saves time, improves consistency, and helps avoid disputes over leave balances. For complex cases (shift changes, unpaid leave, maternity/paternity interactions, carry-over, or statutory minimum checks), confirm with HR or legal guidance.