OSHA hours-worked guidance
Worked-hours estimator
Estimate a group’s actual regular and additional hours for a defined reporting period.
YOUR INPUTS
Set the scope. Enter the data.
Calculator inputs stay in this page’s browser memory and clear on reload. No sign-in required.
YOUR RESULT
A result you can trace.
Enter your data and select Calculate. Your result will show the formula, units and interpretation alongside the definitions and sources below.
No automatic “safe” rating or compliance certificate.
UNDERSTAND THE METRIC
Definition
Worked hours are the hours people actually worked. Paid leave and other paid time without work do not belong in the denominator used for OSHA incidence rates.
When to use it
Use this as a transparent estimate when complete worked-hours records are unavailable. Use separate calculations for groups with different schedules, then combine non-overlapping totals. Prefer actual records when available.
Formula
Estimated worked hours = workers × days actually worked per worker × regular worked hours per day + additional hours for the whole group.
USE IT CONSISTENTLY
Inputs and interpretation
- This grouped estimator is Sentivo’s adaptation of the estimation approach in OSHA’s Form 300A worksheet; it does not replace the underlying records.
- Enter regular hours actually worked, excluding non-working breaks, leave and holidays. Enter additional overtime hours for the whole group, not per person. Do not add overtime again if it is already included in the daily-hours figure.
- Use one workforce scope and reporting period. OSHA’s worksheet includes salaried, hourly, part-time and seasonal workers, and other workers under the establishment’s day-to-day supervision, such as qualifying temporary workers.
- An estimate of zero hours is not a valid denominator for an injury incidence rate.
Sources
Technical references checked on 31 October 2026. OSHA sources establish the methods or guidance described above; they do not constitute OSHA approval or endorsement of this calculator.