Standard statutory minimum in many regions is 28 days (including bank holidays).
Full Year (12 Months)
11 Months
10 Months
9 Months
8 Months
7 Months
6 Months
5 Months
4 Months
3 Months
2 Months
1 Month
Select less than 12 if the employee started or left mid-year.
Base Entitlement:0 days
Pro Rata Factor:0%
Exact Calculated Entitlement:0 days
Understanding Pro Rata Holiday Entitlement
Calculating holiday entitlement for part-time staff or employees who start part-way through the year can be complex. "Pro rata" simply means "in proportion." This calculator helps businesses and employees determine fair holiday allowances based on the proportion of a full-time week worked.
Note: This calculator is designed for workers with fixed working hours. For casual workers or zero-hours contracts, an accrual system (often 12.07% of hours worked) is typically used instead.
How the Calculation Works
The standard formula for calculating pro rata holiday entitlement is straightforward but requires accurate inputs regarding the full-time equivalent role and the specific employee's schedule.
The Formula
The calculation follows three main steps:
Determine the Full-Time Entitlement: This is the total number of days a full-time employee receives per year (e.g., 28 days in the UK, often including bank holidays).
Calculate the Pro Rata Ratio: Divide the employee's working days by the standard full-time working days. (Employee Days ÷ Full Time Days)
Apply the Year Fraction: If the employee has not worked a full year (starting or leaving mid-year), multiply the result by the fraction of the year employed. (Months Worked ÷ 12)
Example Scenarios
Scenario 1: Part-Time Worker (Full Year)
Imagine an employee working 3 days a week. The company standard is 5 days a week with 28 days of holiday.
Calculation: (3 ÷ 5) × 28 = 16.8 days.
Result: The employee is entitled to 16.8 days of annual leave.
Scenario 2: Mid-Year Start
An employee works full-time (5 days) but starts 3 months into the holiday year, meaning they work for only 9 months of that year.
Calculation: 28 × (9 ÷ 12) = 21 days.
Result: The employee gets 21 days for that specific holiday year.
Rounding Holiday Days
Calculations often result in decimal figures (e.g., 16.8 days). Employers cannot round holiday entitlement down. It is legal to keep the fraction (e.g., giving 16.8 days where 0.8 represents a partial day off or financial compensation upon leaving), or many employers choose to round up to the nearest half or full day to simplify administration.
Frequently Asked Questions
Does pro rata include Bank Holidays?
Yes, usually. Statutory entitlement (like the UK's 5.6 weeks / 28 days) includes public holidays. Part-time workers are entitled to a pro-rata portion of these bank holidays, regardless of whether they work on the days the bank holidays fall.
What about casual workers?
For workers with irregular hours, it is often difficult to predict "days per week." In these cases, holiday pay is often calculated based on hours worked, typically accruing at a rate of 12.07% of hours worked (based on the standard 5.6 weeks entitlement).
function calculateHoliday() {
// Get input values using var
var annualEntitlement = parseFloat(document.getElementById('annualEntitlement').value);
var fullTimeDays = parseFloat(document.getElementById('fullTimeDays').value);
var employeeDays = parseFloat(document.getElementById('employeeDays').value);
var monthsEmployed = parseFloat(document.getElementById('monthsEmployed').value);
// Validation logic
if (isNaN(annualEntitlement) || isNaN(fullTimeDays) || isNaN(employeeDays) || isNaN(monthsEmployed)) {
alert("Please enter valid numbers for all fields.");
return;
}
if (fullTimeDays 7 || fullTimeDays > 7) {
alert("Working days per week cannot exceed 7.");
return;
}
// Core Calculation
// 1. Calculate the ratio of work (Part-time factor)
var workRatio = employeeDays / fullTimeDays;
// 2. Calculate the portion of the year worked
var yearRatio = monthsEmployed / 12;
// 3. Calculate total entitlement
var calculatedEntitlement = annualEntitlement * workRatio * yearRatio;
// Format results
var exactResult = calculatedEntitlement.toFixed(2);
// Calculate percentage for display
var percentageRatio = (workRatio * yearRatio * 100).toFixed(1);
// Display results
var resultContainer = document.getElementById('resultContainer');
var baseResultEl = document.getElementById('baseResult');
var factorResultEl = document.getElementById('factorResult');
var finalResultEl = document.getElementById('finalResult');
baseResultEl.innerHTML = annualEntitlement + " days (Full Time)";
factorResultEl.innerHTML = percentageRatio + "% of Full Time";
finalResultEl.innerHTML = exactResult + " days";
// Show the result container
resultContainer.style.display = "block";
}