BIZOMAT Tools · Decide
Risk Rating (5 × 5 matrix)
How serious is this risk?
Rates a risk on a 5 × 5 likelihood and consequence matrix and suggests the response for its band.
Open the calculatorRuns in your browser. No account needed.
How this tool works
Inputs, units and where to find them
| Input | Unit | Typical source |
|---|---|---|
| Likelihood | 1–5 score | Your organisation’s likelihood scale (1 rare, 5 almost certain) |
| Consequence | 1–5 score | Your organisation’s consequence scale (1 minor, 5 severe) |
What each input means
Open an input to see what it is, its units, the worked example and the common mistakes, with a small diagram.
What this means: Likelihood
- What it is
- How likely the risk event is to happen, rated on your organisation’s scale from 1 (rare) to 5 (almost certain).
- Units and format
- Move the slider to a score from 1 (low) to 5 (high).
- Example
- The form opens with 3 as a worked example. It is an illustration, not a recommended value: replace it with your own figure.
- Effect on the result
- Multiplied by the consequence rating to give the score out of 25.
- Get it right
- Use your organisation’s written likelihood descriptors so different people rate the same way.
What this means: Consequence
- What it is
- How bad the outcome would be if the risk happened, rated on your organisation’s scale from 1 (minor) to 5 (severe).
- Units and format
- Move the slider to a score from 1 (low) to 5 (high).
- Example
- The form opens with 4 as a worked example. It is an illustration, not a recommended value: replace it with your own figure.
- Effect on the result
- Multiplied by likelihood to give the score out of 25.
- Get it right
- Rate the realistic worst credible outcome with current controls, using your defined consequence descriptors.
Method and formulas
- Risk score = likelihood × consequence
- Low 1–6, medium 7–14, high 15–25 (adjust to your criteria)
Limitations
- Matrices compress information and can rank risks inconsistently
- Bands are defaults, not your organisation’s risk appetite
- Severe consequences need controls even at low likelihood
Typical uses
- Risk registers
- Pre-start and project risk workshops
- Prioritising controls
Who it is for
- Project and operations managers
- Safety and quality staff
- Risk owners
What you get
- LOW, MEDIUM or HIGH risk
- Score out of 25
- Banding table and response
Interpreting the result
- Use defined descriptors so different people score consistently
- Re-rate residual risk after controls
References
- AS ISO 31000:2018 Risk management — Guidelines
- Cox L. A., “What’s wrong with risk matrices?”, Risk Analysis 28(2), 2008
Learn the Concepts Behind This Tool
These BIZOMAT Library readings explain the method this tool uses, with worked examples.
Explains the concept · Library collection
What a risk score cannot tell you: averages, rare disasters and different kinds of uncertainty
In Risk, Controls and Assurance
What it covers: Likelihood times consequence ranks risks as if the business could average out its losses. Why that hides the risks that could end it, and how to match responses to each kind of uncertainty.
BIZOMAT tools are screening and decision-support utilities. Verify important financial, engineering, safety, legal or operational decisions using appropriate professional standards and your organisation’s approved data.