Calculate your organization's Serious Injury and Fatality frequency rate.
200,000 Hours (OSHA Standard / 100 Employees)
1,000,000 Hours (Common for Large Enterprises)
Please enter valid non-negative numbers for incidents and hours.
Calculated SIF Rate
0.00
function calculateSIFRate() {
var incidentsInput = document.getElementById('sif_incidents');
var hoursInput = document.getElementById('total_hours');
var factorInput = document.getElementById('normalization_factor');
var resultDiv = document.getElementById('sif_results');
var rateDisplay = document.getElementById('sif_rate_display');
var explanationDisplay = document.getElementById('sif_explanation_text');
var errorDiv = document.getElementById('sif_error');
var incidents = parseFloat(incidentsInput.value);
var hours = parseFloat(hoursInput.value);
var factor = parseFloat(factorInput.value);
// Validation
if (isNaN(incidents) || isNaN(hours) || hours <= 0 || incidents < 0) {
errorDiv.style.display = 'block';
resultDiv.style.display = 'none';
return;
}
errorDiv.style.display = 'none';
// Calculation: (Incidents * Factor) / Hours
var sifRate = (incidents * factor) / hours;
// Formatting
// Standard safety rates are usually displayed to 2 or 3 decimal places
var formattedRate = sifRate.toFixed(2);
rateDisplay.innerHTML = formattedRate;
var factorText = (factor === 200000) ? "200,000" : "1,000,000";
explanationDisplay.innerHTML = "This means there are " + formattedRate + " Serious Injuries or Fatalities for every " + factorText + " hours worked by your workforce.";
resultDiv.style.display = 'block';
}
What is a SIF Rate?
The SIF Rate (Serious Injury and Fatality Rate) is a critical safety metric used to measure the frequency of high-severity incidents within an organization. Unlike the Total Recordable Incident Rate (TRIR), which treats all injuries equally (from minor cuts to broken bones), the SIF Rate specifically isolates incidents that resulted in life-threatening injuries, permanent disabilities, or fatalities.
Tracking SIF helps Environmental, Health, and Safety (EHS) professionals focus on the precursors that lead to the most severe consequences, rather than getting lost in the noise of minor, low-severity incidents.
How to Calculate SIF Rate
The formula for calculating the SIF Rate follows standard OSHA incidence rate methodologies:
SIF Rate = (Number of SIF Incidents × Normalization Factor) ÷ Total Hours Worked
Where:
Number of SIF Incidents: The total count of fatalities and serious injuries (such as amputations, severe burns, or fractures) during the specified period.
Total Hours Worked: The aggregate hours worked by all employees (and sometimes contractors) during that same period.
Normalization Factor: usually 200,000 (representing 100 full-time employees working 40 hours a week for 50 weeks) or 1,000,000 (often used by larger international organizations or specifically for fatality rates).
Example Calculation
Imagine a construction company has 500 employees. Over the course of a year, they worked a total of 1,000,000 hours. Unfortunately, they experienced 2 serious injuries during this time.
Using the standard 200,000 normalization factor:
(2 Incidents × 200,000) ÷ 1,000,000 Hours
400,000 ÷ 1,000,000 = 0.40
Their SIF Rate is 0.40.
Why SIF vs. TRIR?
Traditionally, safety programs believed in the Heinrich Triangle theory—that reducing minor accidents would automatically reduce major ones. However, modern safety science suggests that SIFs often have different root causes than minor injuries. You can have a very low TRIR (few minor injuries) but still have a high risk of fatality due to unaddressed critical risks. Calculating the SIF Rate separately ensures these high-stakes risks are not ignored.