The standard Likelihood × Severity matrix used in UK risk assessments. Pick your scores below to see the risk band and what action to take next.
Risk score
9Medium
Likelihood 3 × Severity 3
What to do: Tolerable with controls. Implement reasonably practicable measures and monitor effectiveness.
Need to record this in a real RAMS?
Riskora's builder applies this matrix automatically across every hazard you select.
Each cell shows the risk score for that combination, colour-coded by band. This is the matrix Riskora uses internally for every hazard.
| S1 | S2 | S3 | S4 | S5 | |
|---|---|---|---|---|---|
| L1 | 1 | 2 | 3 | 4 | 5 |
| L2 | 2 | 4 | 6 | 8 | 10 |
| L3 | 3 | 6 | 9 | 12 | 15 |
| L4 | 4 | 8 | 12 | 16 | 20 |
| L5 | 5 | 10 | 15 | 20 | 25 |
L = Likelihood (rows). S = Severity (columns).
The 5×5 risk matrix is a long-standing convention in UK occupational safety, derived from the principles in the Management of Health and Safety at Work Regulations 1999 (Regulation 3 — duty to make a "suitable and sufficient" risk assessment). The HSE does not mandate any specific matrix size, but 5×5 is widely used because it gives enough granularity to distinguish trivial hazards from serious ones without becoming unwieldy.
The score itself is not the assessment — it's a way to communicate the assessment. Two assessors using the same matrix will sometimes disagree on the inputs, which is why competent judgement matters. The score should always be paired with documented control measures.