1 – Negligible
2 – Minor
4 – Moderate
7 – Major
10 – Catastrophic
Risk Analysis Results
Risk Rate: 0%
Risk Score (Priority Index): 0 / 10
Understanding the Risk Rate Calculation
A Risk Rate is a quantitative measure used to determine the frequency or probability of a specific hazard occurring within a defined population or timeframe. Unlike qualitative assessments that rely on subjective terms like "High" or "Low," a quantitative risk rate provides data-driven insights that are essential for project management, insurance underwriting, and health and safety compliance.
How to Calculate Risk Rate
The fundamental formula for determining the risk rate is:
Risk Rate (%) = (Total Number of Incidents / Total Exposure) × 100
To further refine this into a Risk Score, we multiply the probability (Rate) by the impact (Severity). This helps organizations prioritize which risks require immediate mitigation versus those that can be simply monitored.
Practical Examples
Workplace Safety: If a factory records 5 incidents over 100,000 man-hours, the incident rate is 0.005% per hour.
Software Development: If 2 major bugs are found in 50 code deployments, the deployment risk rate is 4%.
Medical Research: If 10 patients out of 1,000 experience side effects, the risk rate for that medication is 1%.
Interpreting the Risk Score
Our calculator assigns a Risk Score based on the interaction between frequency and severity:
Risk Score
Category
Action Required
0.0 – 1.5
Low
Acceptable; Routine monitoring.
1.6 – 4.5
Medium
Mitigation plans required.
4.6 – 10.0
High
Immediate intervention mandatory.
function calculateRisk() {
var incidents = parseFloat(document.getElementById('occurrences').value);
var exposure = parseFloat(document.getElementById('exposure').value);
var severity = parseFloat(document.getElementById('impactScale').value);
var resultDiv = document.getElementById('riskResult');
var resRate = document.getElementById('resRate');
var resScore = document.getElementById('resScore');
var riskLevel = document.getElementById('riskLevel');
if (isNaN(incidents) || isNaN(exposure) || exposure <= 0) {
alert("Please enter valid positive numbers for incidents and exposure.");
return;
}
// Calculation Logic
var rate = (incidents / exposure) * 100;
// Risk Score logic: (Normalized probability x Severity)
// We cap the probability factor to 1.0 (100%) for the score indexing
var probFactor = Math.min(rate / 100, 1);
var score = probFactor * severity;
// Display results
resRate.innerText = rate.toFixed(4);
resScore.innerText = score.toFixed(2);
resultDiv.style.display = 'block';
resultDiv.style.backgroundColor = '#fdfdfd';
resultDiv.style.border = '1px solid #eee';
// Categorization
if (score < 1.5) {
riskLevel.innerText = "LOW RISK";
riskLevel.style.backgroundColor = "#27ae60";
} else if (score < 4.5) {
riskLevel.innerText = "MEDIUM RISK";
riskLevel.style.backgroundColor = "#f39c12";
} else {
riskLevel.innerText = "HIGH RISK";
riskLevel.style.backgroundColor = "#c0392b";
}
}