A Risk matrix is a matrix that is used during risk assessment to define the various levels of risk as the product of the harm probability categories and harm severity categories. This is a simple mechanism to increase visibility of risks and assist management decision making.
Risk Matrix Chart Diagram
Likelihood = How likely is the event of risk to occur
Rare / Very Unlikely = Only in exceptional circumstances
Unlikely = Might occur in future time
Moderate /Possible = Might occur at some time
Likely = Probably occur in most circumstances
Very likely = Almost certain = Expected in most circumstances
Impact = A marked effect or influence
Negligible = No injuries, No damages
Minor = Minor injuries, Minor damages, First aid required
Moderate = Some injuries, Medium damages, Medical help necessary
Major / Significant = Extensive injuries, High damages, Medical help necessary
Extreme / Severe = Death or major injuries, High level damages, Medical help necessary
Note: Above 'Risk Matrix Chart Diagram' is an example. Every organization may have its own Risk Matrix Chart.