Risk Matrix / Risk Score Calculator
Formula Reference
Risk Score = Likelihood × SeverityStandard Risk Level Bands (this tool's default convention)
| Low | Bottom quartile of possible scores |
| Medium | Second quartile |
| High | Third quartile |
| Extreme | Top quartile |
A Note on Matrix Design
This tool uses a simple, symmetric Likelihood × Severity product with quartile-based bands, since it's a widely understood default. Many real organizational risk matrices are asymmetric — deliberately weighting severity more heavily than likelihood, so a rare-but-catastrophic event (e.g., Likelihood 1 × Severity 5) is treated as higher risk than a frequent-but-trivial one (Likelihood 5 × Severity 1), even though the arithmetic product is identical. If your organization has an approved risk matrix with specific cell-by-cell risk levels, use that as the definitive reference — this calculator is a general-purpose default, not a substitute for your documented risk assessment procedure.Methodology, interpretation & sources
Purpose. Calculates a risk score from Likelihood × Severity, classifies it against a standard risk-level banding, and shows exactly where it falls on a visual risk matrix.
How to use the result. Start with source data you can verify, enter values on a consistent unit and time basis, and record the assumptions used. The main inputs on this page include Matrix Size 5×5 is the most common convention; 3×3 and 4×4 are simpler alternatives some organizations use., Likelihood, Severity / Consequence, Your Name, Email, Company Name. Re-run the calculation when those assumptions change rather than carrying an old result forward.
Decision use. Use this calculator as a structured process-safety screening aid. It does not replace a formal PHA, QRA, LOPA or competent engineering review when those methods are required.
Limitations. Event definitions, consequence assumptions, exposure frequencies, safeguards and uncertainty should be documented so that the result can be independently reviewed.
Primary references. Use the current edition/version that applies to your jurisdiction and organization:
Editorial note. Prepared and maintained by Impact Tech Solutions. Editorially updated 28 September 2026. No individual professional credential is claimed on this page; high-consequence, statutory, tax, engineering or health decisions should be independently verified against the current primary source and, where required, a qualified professional.