body {
font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
line-height: 1.6;
color: #333;
max-width: 800px;
margin: 0 auto;
padding: 20px;
background-color: #f9f9f9;
}
.calculator-container {
background: #ffffff;
padding: 30px;
border-radius: 12px;
box-shadow: 0 4px 6px rgba(0,0,0,0.1);
margin-bottom: 40px;
}
.input-group {
margin-bottom: 20px;
}
label {
display: block;
margin-bottom: 8px;
font-weight: 600;
color: #2c3e50;
}
input[type="number"] {
width: 100%;
padding: 12px;
border: 1px solid #ddd;
border-radius: 6px;
font-size: 16px;
box-sizing: border-box;
}
.btn-calc {
width: 100%;
background-color: #3498db;
color: white;
border: none;
padding: 15px;
font-size: 18px;
font-weight: bold;
border-radius: 6px;
cursor: pointer;
transition: background-color 0.3s;
}
.btn-calc:hover {
background-color: #2980b9;
}
.results-area {
margin-top: 25px;
padding: 20px;
background-color: #f0f7fb;
border-radius: 8px;
border-left: 5px solid #3498db;
display: none;
}
.result-row {
display: flex;
justify-content: space-between;
margin-bottom: 10px;
padding-bottom: 10px;
border-bottom: 1px solid #dae1e7;
}
.result-row:last-child {
border-bottom: none;
margin-bottom: 0;
padding-bottom: 0;
}
.result-label {
font-weight: 500;
color: #555;
}
.result-value {
font-weight: 700;
color: #2c3e50;
}
.article-content {
background: #fff;
padding: 30px;
border-radius: 12px;
box-shadow: 0 2px 4px rgba(0,0,0,0.05);
}
h1, h2, h3 {
color: #2c3e50;
}
.formula-box {
background: #eee;
padding: 15px;
border-radius: 5px;
font-family: monospace;
margin: 15px 0;
}
@media (max-width: 600px) {
.calculator-container {
padding: 20px;
}
}
function calculateProRata() {
// Get input values
var ftHours = parseFloat(document.getElementById('ftHours').value);
var ptHours = parseFloat(document.getElementById('ptHours').value);
var ftSalary = parseFloat(document.getElementById('ftSalary').value);
var ftHoliday = parseFloat(document.getElementById('ftHoliday').value);
// Output elements
var resFTE = document.getElementById('resFTE');
var resPercent = document.getElementById('resPercent');
var resSalary = document.getElementById('resSalary');
var resWeekly = document.getElementById('resWeekly');
var resHoliday = document.getElementById('resHoliday');
var resultsArea = document.getElementById('results');
// Validation
if (isNaN(ftHours) || ftHours <= 0) {
alert("Please enter a valid number for Standard Full-Time Hours.");
return;
}
if (isNaN(ptHours) || ptHours < 0) {
alert("Please enter a valid number for Your Contracted Hours.");
return;
}
// Defaults for optional fields if left blank
if (isNaN(ftSalary)) ftSalary = 0;
if (isNaN(ftHoliday)) ftHoliday = 0;
// Logic
// 1. Calculate Ratio (FTE)
var fteRatio = ptHours / ftHours;
// 2. Calculate Percentage
var percentage = fteRatio * 100;
// 3. Calculate Pro Rata Salary
var proRataSalary = ftSalary * fteRatio;
// 4. Calculate Weekly Pay (Annual / 52)
var weeklyPay = proRataSalary / 52;
// 5. Calculate Pro Rata Holiday
var proRataHoliday = ftHoliday * fteRatio;
// Display Results
resFTE.textContent = fteRatio.toFixed(4);
resPercent.textContent = percentage.toFixed(2) + "%";
// Format Currency
var currencyFormatter = new Intl.NumberFormat('en-US', {
style: 'currency',
currency: 'USD', // You can change this to GBP or EUR as needed
minimumFractionDigits: 2
});
resSalary.textContent = currencyFormatter.format(proRataSalary);
resWeekly.textContent = currencyFormatter.format(weeklyPay);
resHoliday.textContent = proRataHoliday.toFixed(1) + " days";
// Show results div
resultsArea.style.display = "block";
}
Understanding Pro Rata Calculations for Part-Time Work
Whether you are an employer drafting a contract or an employee considering reducing your hours, understanding how to calculate pro rata entitlements is crucial. "Pro rata" simply means "in proportion." It ensures that part-time workers receive fair pay and benefits proportional to their full-time counterparts.
What is Pro Rata Salary?
A pro rata salary is the adjusted payment amount a part-time employee receives based on the full-time equivalent (FTE) salary for that role. Instead of being paid a fixed part-time rate, the salary is calculated as a fraction of the full-time package.
The Pro Rata Formula
To calculate your pro rata salary manually, you need to determine your "Pro Rata Ratio" first:
Ratio = Part-Time Hours / Full-Time Standard Hours
Once you have the ratio, multiply it by the full-time annual salary:
Pro Rata Salary = Full-Time Salary × Ratio
Example Calculation
Imagine a job offers a full-time salary of $40,000 for a standard 40-hour week. You want to work 3 days a week, totaling 24 hours.
- Step 1: Divide 24 by 40 to get the ratio: 0.6 (or 60%).
- Step 2: Multiply $40,000 by 0.6.
- Result: Your pro rata salary would be $24,000.
Calculating Pro Rata Holiday Entitlement
Holiday pay and leave entitlements are also calculated on a pro rata basis. Most labor laws mandate that part-time workers cannot be treated less favorably than full-time workers.
If a full-time employee gets 28 days of holiday per year, and you work exactly half their hours (0.5 FTE), you are entitled to 14 days of holiday.
Bank Holidays and Part-Time Work
Calculating bank holidays can be tricky for part-time workers who don't work on Mondays. To ensure fairness, many companies give a pro rata allowance for bank holidays added to the total annual leave entitlement, calculated in hours rather than days.
Why Use a Pro Rata Calculator?
Manual calculations can be prone to errors, especially when dealing with odd working hours (e.g., 22.5 hours per week). Using the tool above helps you instantly visualize:
- FTE Score: Your workload relative to a full-time employee.
- Exact Earnings: What your gross annual and weekly pay will look like.
- Benefits: Exactly how many days off you are entitled to.
Frequently Asked Questions
Does pro rata apply to bonuses?
Generally, yes. If a bonus is performance-based on individual sales, you get what you earn. However, if it is a company-wide flat bonus (e.g., a Christmas bonus), part-time employees usually receive a pro rata amount based on their hours.
How do I calculate hourly rate from pro rata salary?
If you know the pro rata salary, simply divide it by 52 (weeks in a year), and then divide that number by your weekly part-time hours. This should equal the hourly rate of the full-time equivalent salary.
Is lunch break included in the hours?
Usually, unpaid lunch breaks are excluded from these calculations. You should input your contracted working hours (paid hours) into the calculator for accurate results.