function calculateSickness() {
// Get Input Values
var employees = parseFloat(document.getElementById('avgEmployees').value);
var periodDays = parseFloat(document.getElementById('workingDays').value);
var sickDays = parseFloat(document.getElementById('totalSickDays').value);
var costPerDay = parseFloat(document.getElementById('dailyCost').value);
// Validation
if (isNaN(employees) || employees <= 0) {
alert("Please enter a valid number of employees.");
return;
}
if (isNaN(periodDays) || periodDays <= 0) {
alert("Please enter the number of working days in the period.");
return;
}
if (isNaN(sickDays) || sickDays 0) {
sicknessRate = (sickDays / totalPotentialDays) * 100;
}
// Total Cost
var totalCost = sickDays * costPerDay;
// Determine Status (General Benchmarks)
var status = "";
if (sicknessRate < 1.5) {
status = "Excellent (Low)";
} else if (sicknessRate < 3.5) {
status = "Average / Acceptable";
} else if (sicknessRate < 5.0) {
status = "High / Needs Attention";
} else {
status = "Critical / Severe";
}
// Update DOM
document.getElementById('rateResult').innerHTML = sicknessRate.toFixed(2) + "%";
document.getElementById('potentialDaysResult').innerHTML = totalPotentialDays.toLocaleString();
document.getElementById('costResult').innerHTML = "$" + totalCost.toLocaleString(undefined, {minimumFractionDigits: 2, maximumFractionDigits: 2});
var statusElement = document.getElementById('statusResult');
statusElement.innerHTML = status;
// Color coding status
if (sicknessRate < 3.5) {
statusElement.style.color = "#38a169"; // Green
} else if (sicknessRate < 5.0) {
statusElement.style.color = "#d69e2e"; // Orange
} else {
statusElement.style.color = "#e53e3e"; // Red
}
document.getElementById('results').style.display = "block";
}
How to Calculate Sickness Absence Rate
Calculating the sickness absence rate (often called the "lost time rate") is a crucial function for HR departments and business owners. It provides a percentage that represents the proportion of working time lost due to staff illness. Understanding this metric helps in benchmarking performance, identifying trends, and managing workforce costs.
The Sickness Rate Formula
The standard formula used globally to calculate the percentage of working time lost is:
(Total Days Lost to Sickness / Total Potential Working Days) × 100 = Sickness Rate %
To use this formula efficiently, you need to break down the components:
Total Days Lost to Sickness: The sum of all days (or hours) absent across the entire group or individual being measured.
Total Potential Working Days: Calculated by multiplying the average number of employees by the number of working days in the specific period (e.g., 20 days for a month, 253 days for a year).
Example Calculation
Imagine a small department with 10 employees. You want to calculate the sickness rate for the month of November, which had 22 working days. During this month, various employees called in sick for a total of 5 days combined.
Calculate Potential Days: 10 employees × 22 days = 220 potential working days.
Divide Lost Days by Potential Days: 5 ÷ 220 = 0.0227.
Convert to Percentage: 0.0227 × 100 = 2.27%.
In this example, the sickness absence rate is 2.27%.
What is a "Good" Sickness Rate?
Benchmarks vary significantly by industry and country. However, general HR guidelines suggest:
Under 1.5%: Exceptionally low. While good for productivity, ensure presenteeism (working while sick) isn't an issue.
1.5% – 3.5%: Considered a healthy, average range for most office-based industries.
Above 4.0%: Indicates potential issues with workplace health, morale, or management that may require intervention.
Why Calculate Sickness Costs?
While the percentage rate monitors frequency, the financial impact is often overlooked. The calculator above includes an estimated cost field. To calculate this accurately, use the "Average Daily Cost per Employee," which should include:
Gross Daily Salary
Employer Taxes/Social Security Contributions
Benefits and Overhead allocations
Direct costs are just the tip of the iceberg. Indirect costs, such as replacement staff, administrative time, and reduced team morale, often make the true cost of absence 2-3 times higher than the direct salary cost.