5×5 Risk Assessment Calculator
Hazards Identified
| Consequence \ Likelihood | 1 | 2 | 3 | 4 | 5 |
|---|---|---|---|---|---|
| 1 | 1 | 2 | 3 | 4 | 5 |
| 2 | 2 | 4 | 6 | 8 | 10 |
| 3 | 3 | 6 | 9 | 12 | 15 |
| 4 | 4 | 8 | 12 | 16 | 20 |
| 5 | 5 | 10 | 15 | 20 | 25 |
Explanation of the 5×5 Risk Matrix
Users must understand what the numbers mean.
🔹 Likelihood Scale (Probability)
Explain clearly:
| Rating | Description | Meaning |
|---|---|---|
| 1 | Rare | May occur only in exceptional circumstances |
| 2 | Unlikely | Could happen, but not expected |
| 3 | Possible | Might occur at some time |
| 4 | Likely | Will probably occur in most circumstances |
| 5 | Almost Certain | Expected to occur frequently |
🔹 Consequence Scale (Severity)
| Rating | Description | Example Impact |
|---|---|---|
| 1 | Insignificant | No injury or very minor issue |
| 2 | Minor | First aid treatment |
| 3 | Moderate | Medical treatment required |
| 4 | Major | Serious injury or permanent disability |
| 5 | Catastrophic | Fatality or multiple serious injuries |
How the Risk Score Is Calculated
Clearly state:
Risk Score = Likelihood × Consequence
Explain:
-
Minimum score = 1
-
Maximum score = 25
-
Higher score = higher priority
Risk Rating Interpretation Guide
Users must know what to do with the result.
Example:
🟢 Low Risk (1–4)
-
Acceptable
-
Maintain existing controls
-
Monitor periodically
🟡 Medium Risk (5–9)
-
Additional controls may be required
-
Supervisor review recommended
🟠 High Risk (10–16)
-
Action required
-
Senior management involvement
🔴 Critical Risk (17–25)
-
Immediate action required
-
Work should stop until the risk is reduced
This is critical. Without this, the matrix is just numbers.
Legal and Compliance Disclaimer
Very important for websites.
Example:
This tool is for guidance purposes only. It does not replace a formal risk assessment conducted by a competent person. Always comply with applicable workplace safety laws and regulations.
This protects you legally.
Limitations of the Tool
Users must understand:
-
It does not automatically identify hazards
-
It does not replace professional judgement
-
It assumes a simple linear risk model
-
It does not account for complex risk variables
Step-by-Step Instructions (Very Important for Users)
After the tool, add:
How to Use This Calculator
-
Identify the hazard.
-
Determine the likelihood of occurrence.
-
Determine the severity of consequences.
-
Click “Calculate Risk.”
-
Review the highlighted matrix position.
-
Apply appropriate control measures.
-
Reassess after implementing controls.
Control Measures Guidance
You should add:
Follow the Hierarchy of Controls
-
Elimination
-
Substitution
-
Engineering Controls
-
Administrative Controls
-
Personal Protective Equipment (PPE)
This aligns with OSHA and ISO standards.
Residual Risk Advice
Add a short note:
After implementing control measures, reassess the risk to determine the residual risk level.
This shows professional understanding.
Record Keeping Reminder
Important for compliance:
All risk assessments should be documented, signed, dated, and reviewed periodically.