Risk Matrix Calculator
Use this calculator to rate a hazard by how likely it is to cause harm and how severe the harm could be. Rate it before and after your controls to see whether they bring the risk down to an acceptable level.
Prepared by Morgan Compliance Group · Published 23 October 2026 · Updated 23 October 2026
Who it's for
Anyone completing or reviewing a risk assessment.
Calculate your risk rating
Choose likelihood and severity for the hazard before and after controls. The scores and 5 x 5 grid update automatically. Nothing you enter is sent to a server.
Before controls
Initial risk rating
Choose likelihood and severity to calculate your score.
After controls
Residual risk rating
Choose likelihood and severity to calculate your score.
Your 5 x 5 risk matrix
Likelihood runs from 1 to 5 down the rows. Severity runs from 1 to 5 across the columns. B marks the risk before controls and A marks the risk after controls.
How to rate likelihood and severity
Rate the hazard realistically for your actual work and the people exposed, not the best-case situation. Severity means the worst realistic harm that could follow. Likelihood depends on how frequently someone is exposed and how reliable the existing safeguards are.
The hierarchy of controls
First consider eliminating the hazard. If that is not possible, look at substitution and then engineering controls. Use administrative measures such as procedures, supervision and training to support the physical protections. Personal protective equipment is the last resort, not the first choice.
A score is not a risk assessment
A risk score helps prioritise attention. A complete assessment also identifies hazards, who might be harmed, the safeguards in place, further action needed, the responsible person and the completion date. Download our editable Risk Assessment Template.
This resource is general guidance. Adapt it to your own business, activities and risks.
Want your risk assessments checked?
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