Job Hazard Analysis Score Calculator

Calculator Inputs

Add hazards, score each factor, then estimate how controls reduce risk.

Example Data Table

Formula Used

How to Use This Calculator

1. Add one hazard per card, using “Add hazard”.
2. Enter the task and the hazard description clearly.
3. Choose Severity, Likelihood, and Exposure from 1–5.
4. Estimate control effectiveness for current controls.
5. Press “Calculate score” to rank hazards by residual risk.
6. Export CSV for tracking or PDF for toolbox briefings.
7. Re-score after new controls to verify improvement.

Professional Article: Job Hazard Analysis Scoring in Construction

A Job Hazard Analysis (JHA) turns observations into repeatable decisions. This calculator standardizes scoring with Severity, Likelihood, and Exposure (1–5 each), then estimates how controls reduce risk. The result is a ranked list you can brief to crews, document for audits, and improve over time. Use it during pre-task planning, permit reviews, and shift handovers to keep risk conversations structured and consistent today.

1) Why scoring matters on active sites

Construction conditions shift quickly: access routes change, plant movements increase, and temporary works evolve. A numeric score helps compare tasks fairly, highlight the highest-risk steps, and justify pauses or method changes. When the team shares one scale, briefings become faster and disagreements reduce.

2) Severity with field-ready benchmarks

Severity reflects the most credible consequence, not the most likely outcome. Typical benchmarks are: 1 first aid, 2 medical treatment, 3 lost-time injury, 4 permanent disability, and 5 fatality or multiple fatalities. Use the same benchmarks across projects to keep scoring consistent.

3) Likelihood based on today’s conditions

Likelihood considers current barriers, housekeeping, congestion, and supervision. A task can shift from 2 to 4 when visibility drops or access is restricted. Use near-miss reports and daily observations to calibrate scoring. If uncertainty remains, select the higher value and validate on site.

4) Exposure captures time and people at risk

Exposure measures how long workers are in the hazard zone and how often they return. Brief access might score 1–2, while repetitive handling or continuous trench work may score 4–5. Exposure often drives risk in production work, so manage it with sequencing and work planning.

5) Raw and residual scores show control impact

The calculator uses Raw = S × L × E (range 1–125). Then it applies Residual = Raw × (1 − Control%/100). Control effectiveness is capped at 90% to avoid false certainty. This approach shows inherent risk and the measurable benefit of improvements.

6) Thresholds guide action and escalation

Residual thresholds support clear decisions: Low <20, Moderate 20–39.99, High 40–79.99, Critical ≥80. For High or Critical items, strengthen engineering controls, tighten access, add competent supervision, or redesign the method. Record who owns each action and when it will be verified. Escalate to site management when controls cannot reduce the score quickly.

7) Ranking, reporting, and continuous improvement

Ranked hazards focus attention on what matters most. Export CSV to track trends by week, activity, or subcontractor. Export PDF for toolbox talks, permits, and client reviews. Re-score after changes to confirm that controls lowered residual risk and that the method remains workable for crews.

FAQs

1) What is a “good” residual score?

Lower is better. Aim to drive residual scores below 20 where feasible, especially for repetitive tasks. If scores remain moderate or higher, add stronger controls or change the work method.

2) Why does the calculator use 1–5 scales?

A 1–5 scale is quick in the field and reduces debate. It also keeps the math simple, producing a raw range of 1–125 that is easy to interpret and compare.

3) How should we estimate control effectiveness?

Combine realistic reductions from engineering, administrative controls, and PPE. Use evidence where possible: inspections, maintenance logs, training records, and supervisor verification. Avoid overestimating; the tool caps at 90%.

4) Should we score before or after controls?

Score the baseline first (raw), then apply control effectiveness to obtain the residual score. This shows both the inherent risk and the impact of your planned controls.

5) What if two hazards have the same residual score?

Treat them as equal priority. Use context to decide next steps, such as the number of people exposed, task duration, or potential for escalation. Consider splitting into more specific hazards.

6) How often should we update a job hazard analysis?

Update whenever conditions change: new crew, different equipment, weather impacts, design changes, or new hazards identified. At minimum, review at the start of each shift and after incidents or near-misses.

7) Can this replace a formal safety procedure?

No. It supports decisions and documentation, but you still need permits, method statements, competent supervision, and compliance with applicable regulations and client requirements.