Calculator Inputs
The page uses a single-column flow, while the form itself uses a responsive 3, 2, and 1 column field layout.
Plotly Graph
The chart highlights the day components behind the current severity result.
Example Data Table
This sample uses a 200,000-hour base and includes restricted workdays in severity days.
| Month | Hours Worked | Lost Days | Restricted Days | Fatalities | Severity Days | Severity Rate |
|---|---|---|---|---|---|---|
| January | 48,000 | 9 | 6 | 0 | 15 | 62.50 |
| February | 52,000 | 4 | 2 | 0 | 6 | 23.08 |
| March | 50,000 | 12 | 5 | 0 | 17 | 68.00 |
| April | 47,000 | 7 | 3 | 0 | 10 | 42.55 |
Formula Used
Severity Days = Lost Workdays + Restricted Workdays Included + (Fatalities × Fatality Weight Equivalent Days)
Incident Severity Rate = (Severity Days × Base Factor) ÷ Total Hours Worked
Lost-Time Severity Rate = (Lost Workdays × Base Factor) ÷ Total Hours Worked
Recordable Case Rate = (Recordable Incidents × Base Factor) ÷ Total Hours Worked
Use the 200,000-hour base for standard workforce comparisons, or switch to 1,000,000 hours for larger enterprise reporting.
How to Use This Calculator
- Enter total hours worked for the reporting period.
- Add lost workdays from workplace incidents.
- Enter restricted-duty days if your policy tracks them.
- Optionally include fatalities and a weighted severity equivalent.
- Choose the reporting base factor that matches your organization.
- Set a benchmark rate and previous rate for performance review.
- Click the calculate button to generate the result summary.
- Download the calculation in CSV or PDF format if needed.
FAQs
1. What does incident severity rate measure?
It measures how serious workplace incidents are by linking lost or restricted days to total hours worked. Higher values usually indicate more severe outcomes per exposure period.
2. Why use hours worked in the formula?
Hours worked standardize the result across teams, departments, or plants. This makes comparisons fairer when headcount and shift lengths differ across reporting periods.
3. Should restricted workdays always be included?
Not always. Some organizations track severity using lost days only, while others include restricted days for a broader impact view. This calculator supports both approaches.
4. What base factor should manufacturers choose?
Use 200,000 hours for common workforce safety reporting. Use 1,000,000 hours when your internal dashboards or enterprise reporting standards prefer a larger exposure base.
5. How is this different from incident rate?
Incident rate focuses on how often incidents occur. Severity rate focuses on how serious those incidents were by using days lost, restricted, or weighted equivalent days.
6. Can this help with trend analysis?
Yes. Enter a previous period rate and a benchmark target to see direction, variance, and percentage change. That makes monthly or quarterly safety reviews easier.
7. Why include fatalities with weighted days?
Some internal systems convert fatalities into a weighted day value to reflect very high impact. This supports advanced scorecards when direct day counting alone is insufficient.
8. Can I use this for a single production line?
Yes. The calculator works for a line, shift, site, or full company. Just keep hours, incident counts, and day totals aligned to the same reporting scope.