.osha-calc-container {
max-width: 800px;
margin: 20px auto;
font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
color: #333;
background: #fff;
border: 1px solid #e2e8f0;
border-radius: 8px;
box-shadow: 0 4px 6px rgba(0,0,0,0.05);
}
.osha-calc-header {
background: #2c5282;
color: white;
padding: 20px;
border-top-left-radius: 8px;
border-top-right-radius: 8px;
text-align: center;
}
.osha-calc-header h2 {
margin: 0;
font-size: 24px;
}
.osha-calc-body {
padding: 30px;
}
.osha-input-group {
margin-bottom: 20px;
}
.osha-input-group label {
display: block;
font-weight: 600;
margin-bottom: 8px;
color: #2d3748;
}
.osha-input-group input {
width: 100%;
padding: 12px;
font-size: 16px;
border: 2px solid #cbd5e0;
border-radius: 6px;
box-sizing: border-box;
transition: border-color 0.2s;
}
.osha-input-group input:focus {
border-color: #4299e1;
outline: none;
}
.osha-calc-btn {
width: 100%;
padding: 14px;
background: #e53e3e;
color: white;
font-size: 18px;
font-weight: bold;
border: none;
border-radius: 6px;
cursor: pointer;
transition: background 0.2s;
}
.osha-calc-btn:hover {
background: #c53030;
}
#oshaResult {
margin-top: 30px;
padding: 20px;
background: #f7fafc;
border-radius: 6px;
border-left: 5px solid #2c5282;
display: none;
}
.osha-result-title {
font-size: 14px;
text-transform: uppercase;
color: #718096;
letter-spacing: 1px;
margin-bottom: 5px;
}
.osha-result-value {
font-size: 32px;
font-weight: 800;
color: #2c5282;
}
.osha-result-desc {
margin-top: 10px;
font-size: 14px;
color: #4a5568;
line-height: 1.5;
}
.osha-article {
max-width: 800px;
margin: 40px auto;
line-height: 1.6;
color: #2d3748;
}
.osha-article h2 {
color: #2c5282;
margin-top: 30px;
border-bottom: 2px solid #edf2f7;
padding-bottom: 10px;
}
.osha-article ul {
background: #f8f9fa;
padding: 20px 40px;
border-radius: 6px;
}
.osha-article code {
background: #edf2f7;
padding: 2px 6px;
border-radius: 4px;
color: #c53030;
font-family: monospace;
}
.helper-text {
font-size: 12px;
color: #718096;
margin-top: 4px;
}
function calculateOSHA() {
var incidentsInput = document.getElementById("recordableIncidents");
var hoursInput = document.getElementById("totalHoursWorked");
var resultDiv = document.getElementById("oshaResult");
var rateDisplay = document.getElementById("resultRate");
var explainDisplay = document.getElementById("resultExplanation");
var incidents = parseFloat(incidentsInput.value);
var hours = parseFloat(hoursInput.value);
if (isNaN(incidents) || isNaN(hours)) {
alert("Please enter valid numbers for both fields.");
return;
}
if (hours <= 0) {
alert("Total hours worked must be greater than zero.");
return;
}
// The OSHA Formula: (Incidents * 200,000) / Hours Worked
var baseConstant = 200000;
var rate = (incidents * baseConstant) / hours;
// Round to 1 decimal place (Standard OSHA reporting format)
var finalRate = rate.toFixed(1);
resultDiv.style.display = "block";
rateDisplay.innerHTML = finalRate;
explainDisplay.innerHTML = finalRate;
}
How to Calculate OSHA Incident Rate
Calculating your OSHA (Occupational Safety and Health Administration) Incident Rate is a critical requirement for safety managers and business owners. This metric, often referred to as the Total Recordable Incident Rate (TRIR), allows companies to compare their safety performance against industry averages regardless of company size.
The OSHA Rate Formula
The standard formula used to calculate the incidence rate is:
(Number of Injuries and Illnesses × 200,000) ÷ Total Hours Worked
Here is a breakdown of the variables:
- Number of Injuries and Illnesses: This is the total count of recordable incidents entered on your OSHA 300 Log for the year. This includes fatalities, days away from work, restricted work activity, medical treatment beyond first aid, and loss of consciousness.
- Total Hours Worked: This is the sum of all actual hours worked by all employees (including full-time, part-time, temporary, and seasonal workers). Do not include vacation, sick leave, or holidays.
- 200,000: This is a constant base number. It represents the equivalent of 100 full-time employees working 40 hours per week for 50 weeks a year (100 × 40 × 50 = 200,000). This standardizes the rate so small and large companies can be compared directly.
Example Calculation
Let's say you run a manufacturing plant with the following data for the calendar year:
- Your team suffered 3 recordable injuries.
- Your total workforce logged 150,000 hours.
Using the calculator above or the formula manually:
(3 × 200,000) ÷ 150,000 = 4.0
Your OSHA Incident Rate is 4.0. This means that for every 100 equivalent full-time workers, 4 employees suffered a recordable injury or illness.
Understanding TRIR vs. DART
While the calculator above determines your Total Recordable Incident Rate (TRIR), there is another specific metric called DART (Days Away, Restricted, or Transferred).
To calculate your DART rate using the tool above, simply change the first input field to only count incidents that resulted in days away from work, restricted job activity, or a transfer to another job. The math remains exactly the same.
Why is this Calculation Important?
Tracking this rate is not just about compliance. A high OSHA rate can lead to:
- Increased scrutiny and inspections from OSHA.
- Higher Workers' Compensation insurance premiums.
- Disqualification from bidding on certain government or private contracts.
Regularly using an OSHA rate calculator helps safety professionals monitor trends month-over-month or year-over-year to validate the effectiveness of safety programs.