Risk Assessment Score Calculator

Score hazards, plan controls, and reduce site risks. Export clear reports for teams. Improve compliance with practical, measurable actions.

Enter hazard details
Use consistent scoring to standardize decisions.
Range: 1 (lowest) to 5 (highest)
How bad is the consequence if it happens?
How likely is the event without new controls?
How often are people exposed to the hazard?
Used to adjust likelihood for the residual score.
Useful for tracking a single assessment.
Reset
Example assessment table
Use these examples to align scoring across teams.
Activity Hazard S L E Initial Eff% Residual Level
Hot workFire / burns433365024Moderate
ExcavationTrench collapse534606040Moderate
LiftingDropped load523304530Moderate
Work at heightFall from edge544807040Moderate
Tip: Agree on scoring definitions during safety briefings to reduce bias.
Formula used
Initial score
Initial = Severity × Likelihood × Exposure
Severity (S): consequence impact. Likelihood (L): chance of occurrence. Exposure (E): how often people are exposed.
Residual score
ResidualLikelihood = ceil(L × (1 − Eff%/100))
Residual = Severity × ResidualLikelihood × Exposure
Eff% represents estimated combined effectiveness of current/planned controls.

Risk bands (1–125)
  • 1–20: Low
  • 21–50: Moderate
  • 51–75: High
  • 76–125: Extreme
Why multiply?
Multiplication penalizes high values strongly, helping teams prioritize work that is both severe and likely, especially when exposure is frequent.
How to use this calculator
  1. Describe the activity and the hazard clearly.
  2. Select severity, likelihood, and exposure using shared definitions.
  3. Estimate control effectiveness based on real controls in place.
  4. Submit to view initial and residual scores above the form.
  5. Use the recommended action to guide next steps on site.
  6. Download CSV/PDF to attach to permits, audits, and briefings.

Risk scoring supports consistent site decisions

Construction teams often rate hazards differently across shifts and subcontractors. A structured score converts judgement into a shared language. By combining severity, likelihood, and exposure, supervisors can compare tasks objectively, document assumptions, and justify control priorities during briefings, audits, and permit reviews. Consistency also helps align client expectations with daily site realities and reduces debate when conditions change. Use the same scales across sites to benchmark performance and guide corrective actions reliably.

Severity, likelihood, and exposure define the baseline

Severity reflects the credible worst outcome, from minor injury to fatality or major damage. Likelihood estimates how often the event could occur with current conditions. Exposure represents how frequently people are in the danger zone. Using one-to-five scales keeps inputs simple while preserving meaningful differentiation. Teams should define each score with examples, such as “edge protection missing” or “lifting over live walkways,” to standardize interpretation.

Residual scoring quantifies the effect of controls

Risk reduction is strongest when controls are engineered, verified, and maintained. The calculator applies an effectiveness percentage to reduce likelihood, then recalculates the residual score. This mirrors real workflows: identify controls, estimate performance, and confirm that the remaining risk is tolerable before work proceeds. Pair the estimate with evidence, such as inspection records, permits, competence cards, and supervision frequency.

Bands and actions improve prioritization and escalation

Scores are grouped into bands that trigger practical actions. Low scores focus on monitoring and routine checks. Moderate scores suggest improving supervision or housekeeping. High scores demand immediate mitigation and formal authorization. Extreme scores indicate stopping the task until controls reduce exposure or likelihood to safe levels. When residual scores remain high, redesign the method, sequence the work differently, or remove workers from the hazard area.

Reporting strengthens compliance and learning cycles

Exported CSV and PDF outputs make results easy to attach to method statements, toolbox talks, and client documentation. Over time, repeated assessments create a dataset showing which activities generate high scores and which controls deliver the best reduction. This supports targeted training, procurement decisions, and continuous improvement. Reviewing trends monthly can reveal recurring weak points, such as poor access control, inadequate housekeeping, or rushed schedule pressure.

FAQs

1) What does the score represent?

It is a priority indicator calculated from severity, likelihood, and exposure. Higher scores mean the hazard needs stronger controls, tighter supervision, or a change in method before work continues.

2) Why include exposure in construction work?

Two hazards with the same severity and likelihood can differ by time-on-task. Exposure captures frequency and duration, helping teams prioritize activities that repeatedly place workers in the danger zone.

3) How should we estimate control effectiveness?

Base it on verified controls, not intentions. Consider engineering measures, permits, inspections, competence, and supervision. Use a conservative percentage when evidence is weak or conditions are variable.

4) Can we change the band thresholds?

Yes. Edit the risk_level() function to match your company matrix. Keep the bands simple so supervisors can remember actions without needing extra charts.

5) Does the calculator replace a formal risk assessment?

No. It supports consistent scoring and documentation. You still need site-specific hazard identification, method statements, permits, and competent review for high-risk activities.

6) What should we do when residual risk is still high?

Stop and reassess. Add stronger controls, redesign the sequence, isolate the area, or substitute the task. Work should only resume when the residual band is acceptable and controls are confirmed.

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Important Note: All the Calculators listed in this site are for educational purpose only and we do not guarentee the accuracy of results. Please do consult with other sources as well.