How is the machine guarding risk score calculated?

It is a weighted average: severity x 0.40 + occurrence x 0.35 + detection x 0.25. With a severity of 8, occurrence of 6, and detection of 7, the score is 3.2 + 2.1 + 1.75 = 7.05.

Why is severity weighted more heavily than the other factors?

Guarding decisions are consequence-driven. An amputation or crush hazard justifies engineering controls even if exposure is infrequent, so severity carries the largest weight (40%) while occurrence (35%) and detection (25%) refine the priority.

What is a good machine guarding risk score?

Lower is better. On a roughly 1-10 scale, scores under about 4 are typically acceptable with existing safeguards, 4-7 warrant scheduled guarding improvements, and above 7 — like the 7.05 in the example — signal a hazard that should move to the top of the remediation list.

How does this differ from a standard RPN?

A traditional FMEA risk priority number multiplies severity, occurrence, and detection into a 1-1000 range that inflates fast and treats all three equally. This model uses a weighted sum on a compact scale that keeps severity dominant and is easier to compare across guards.

What does the detectability rating mean here?

It rates how hard the hazard is to notice or avoid before contact — a fast, silent, hidden pinch point scores high (bad), while an obvious, slow, clearly marked hazard scores low. Higher detectability ratings raise the overall risk because the worker is less likely to react in time.

Can I use this to prove a guard is adequate?

Use it to prioritize and document, not to certify. A dropping score after adding an interlock is good evidence of risk reduction, but adequacy still depends on meeting the applicable OSHA 1910 Subpart O and ANSI/ISO safeguarding requirements for that machine.

Safety & Workforce calculator

Machine Guarding Risk Calculator

Machine guarding risk scoring turns three judgment calls — how badly an unguarded hazard could hurt someone, how often a worker is exposed, and how likely the hazard is to be spotted before contact — into one weighted number you can rank and act on. Safety engineers, manufacturing supervisors, and machine-safety assessors use it during guarding audits and new-equipment risk assessments to decide which nip points, pinch points, and rotating parts get safeguarded first. It matters because guarding budgets and engineering time are finite, and 'fix everything' is not a plan; a defensible score tells you where a fixed guard, interlock, or light curtain buys the most risk reduction per dollar.

What this calculator does

Score machine guarding risk from severity, exposure, and detection factors.
Use it when machine guarding risk in safety and workforce needs a defensible ranking against other safety and workforce risks for the next review.
It computes a single weighted machine-guarding risk score by combining an injury severity rating (40%), an exposure occurrence rating (35%), and a hazard detectability rating (25%).

Formula used

Weighted score = severity × 0.40 + occurrence × 0.35 + detection × 0.25

Inputs explained

Injury severity rating:
Exposure occurrence rating:
Hazard detectability rating:

How to use the result

Use it during a machine-guarding audit or ISO 12100-style risk assessment to rank multiple hazards on one machine, or to compare guarding priorities across a line of equipment.
The weights and the input ratings are subjective; two assessors can score the same guard differently, so calibrate your rating scale and have a second reviewer sanity-check high-consequence hazards rather than trusting the number alone.

Current U.S. benchmarks

Manufacturing hourly earnings average $30.27 (BLS, Jun 2026), up 4.4% from a year earlier. Median machinist pay is $28.24/hr (OEWS 2025), with state medians on each state page. Manufacturers have 529k open positions nationally (BLS JOLTS).

Common questions

How is the machine guarding risk score calculated? It is a weighted average: severity x 0.40 + occurrence x 0.35 + detection x 0.25. With a severity of 8, occurrence of 6, and detection of 7, the score is 3.2 + 2.1 + 1.75 = 7.05.
Why is severity weighted more heavily than the other factors? Guarding decisions are consequence-driven. An amputation or crush hazard justifies engineering controls even if exposure is infrequent, so severity carries the largest weight (40%) while occurrence (35%) and detection (25%) refine the priority.
What is a good machine guarding risk score? Lower is better. On a roughly 1-10 scale, scores under about 4 are typically acceptable with existing safeguards, 4-7 warrant scheduled guarding improvements, and above 7 — like the 7.05 in the example — signal a hazard that should move to the top of the remediation list.
How does this differ from a standard RPN? A traditional FMEA risk priority number multiplies severity, occurrence, and detection into a 1-1000 range that inflates fast and treats all three equally. This model uses a weighted sum on a compact scale that keeps severity dominant and is easier to compare across guards.
What does the detectability rating mean here? It rates how hard the hazard is to notice or avoid before contact — a fast, silent, hidden pinch point scores high (bad), while an obvious, slow, clearly marked hazard scores low. Higher detectability ratings raise the overall risk because the worker is less likely to react in time.

Last reviewed 2026-05-12.