Use this calculator to determine the total work hours between a start and end time, accounting for any breaks. This is ideal for employees, employers, and payroll administrators to accurately track time worked.
.calculator-container {
font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
background-color: #f9f9f9;
padding: 25px;
border-radius: 10px;
box-shadow: 0 4px 12px rgba(0, 0, 0, 0.1);
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margin: 30px auto;
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margin-bottom: 25px;
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.calc-input-group {
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.calc-input-group input[type="text"],
.calc-input-group input[type="number"] {
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transition: border-color 0.3s ease;
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.calc-input-group input[type="text"]:focus,
.calc-input-group input[type="number"]:focus {
border-color: #007bff;
outline: none;
box-shadow: 0 0 5px rgba(0, 123, 255, 0.2);
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.calc-button {
display: block;
width: 100%;
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color: white;
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border-radius: 6px;
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margin-top: 25px;
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.calc-button:hover {
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.calc-button:active {
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.calc-result {
margin-top: 30px;
padding: 20px;
background-color: #e9f7ef;
border: 1px solid #d4edda;
border-radius: 8px;
font-size: 1.15em;
color: #155724;
text-align: center;
font-weight: bold;
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.calc-result strong {
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function parseTime(timeString) {
var timeRegex = /(\d{1,2}):(\d{2})\s*(AM|PM)/i;
var match = timeString.match(timeRegex);
if (!match) {
return NaN; // Invalid time format
}
var hours = parseInt(match[1], 10);
var minutes = parseInt(match[2], 10);
var ampm = match[3].toUpperCase();
if (hours 12 || minutes 59) {
return NaN; // Invalid hour or minute range
}
if (ampm === 'PM' && hours !== 12) {
hours += 12;
} else if (ampm === 'AM' && hours === 12) { // Midnight (12 AM)
hours = 0;
}
return hours * 60 + minutes; // Total minutes from midnight
}
function formatMinutesToHHMM(totalMinutes) {
if (totalMinutes < 0) {
return "00:00"; // Should not happen with current logic, but as a safeguard
}
var hours = Math.floor(totalMinutes / 60);
var minutes = totalMinutes % 60;
var formattedHours = String(hours).padStart(2, '0');
var formattedMinutes = String(minutes).padStart(2, '0');
return formattedHours + ":" + formattedMinutes;
}
function calculateWorkHours() {
var startTimeStr = document.getElementById('startTime').value;
var endTimeStr = document.getElementById('endTime').value;
var breakDurationInput = document.getElementById('breakDuration').value;
var startMinutes = parseTime(startTimeStr);
var endMinutes = parseTime(endTimeStr);
var breakMinutes = parseFloat(breakDurationInput);
var resultDiv = document.getElementById('result');
if (isNaN(startMinutes) || isNaN(endMinutes)) {
resultDiv.innerHTML = "Error: Invalid Start or End Time format. Please use HH:MM AM/PM (e.g., 09:00 AM).";
return;
}
if (isNaN(breakMinutes) || breakMinutes < 0) {
resultDiv.innerHTML = "Error: Invalid Break Duration. Please enter a non-negative number for minutes.";
return;
}
var totalShiftMinutes = endMinutes – startMinutes;
// Handle overnight shifts (e.g., 10 PM to 6 AM)
if (totalShiftMinutes < 0) {
totalShiftMinutes += (24 * 60); // Add 24 hours in minutes
}
var netWorkMinutes = totalShiftMinutes – breakMinutes;
if (netWorkMinutes < 0) {
netWorkMinutes = 0; // A break cannot make you work negative hours
}
var formattedHoursMinutes = formatMinutesToHHMM(netWorkMinutes);
var decimalHours = (netWorkMinutes / 60).toFixed(2);
resultDiv.innerHTML = "Total Work Hours: " + formattedHoursMinutes + " (or " + decimalHours + " decimal hours)";
}
Understanding Time Clocks and Hour Calculation
Time clocks are essential tools for businesses to track employee work hours accurately. Whether physical punch clocks or modern digital systems, their primary function is to record when an employee starts and ends their shift, and often, when they take breaks. Accurate hour calculation is crucial for several reasons:
Payroll Accuracy: Ensures employees are paid correctly for the exact time they've worked, preventing underpayment or overpayment.
Compliance: Helps businesses comply with labor laws regarding minimum wage, overtime, and break requirements.
Budgeting & Cost Control: Provides data for managing labor costs and optimizing staffing levels.
Productivity Analysis: Offers insights into workforce efficiency and resource allocation.
How This Calculator Works
This calculator simplifies the process of determining net work hours. You simply input:
Start Time: The exact time an employee began their shift (e.g., 09:00 AM).
End Time: The exact time an employee finished their shift (e.g., 05:30 PM).
Break Duration: The total time taken for breaks during the shift, specified in minutes. This duration is subtracted from the gross shift time.
The calculator then processes these inputs, handles potential overnight shifts, and subtracts the break time to provide the total net work hours in both HH:MM format and as a decimal value.