Severity Rate Calculator
Formula: Severity Rate = (Lost Workdays × 1,000,000 or 200,000) ÷ Total Hours Worked
What is Severity Rate?
The Severity Rate is a workplace safety metric used to measure the seriousness of injuries by calculating the number of lost workdays due to occupational incidents. Unlike frequency-based metrics that focus on how often incidents happen, severity rate focuses on how serious those incidents are.
The Severity Rate Calculator helps safety professionals assess the true impact of workplace injuries and identify areas needing urgent intervention.
Why is Severity Rate Important?
Tracking severity rate is vital because it:
- Reveals the impact of injuries on productivity and workforce health
- Supports regulatory reporting (e.g., OSHA compliance)
- Highlights serious injury trends that require immediate attention
- Helps evaluate the effectiveness of safety programs
- Guides resource allocation for hazard mitigation
Severity Rate Formula
The standard formula to calculate severity rate is:
Lost Workdays X 200,000 / Total Hours Worked
Where:
- Lost Workdays = Total days employees were unable to work due to injury or illness
- Total Hours Worked = Total employee hours worked during the period
- 200,000 = The annual work hours for 100 full-time employees (40 hrs/week × 50 weeks × 100 employees)
How to Lower Your Severity Rate
To reduce severity rate and improve workplace health:
- Train workers in hazard recognition and injury prevention
- Address high-risk activities through engineering or administrative controls
- Provide proper PPE and ergonomic support
- Investigate incidents thoroughly to prevent recurrence
- Implement early-return-to-work programs
