Why estimate hours worked?
Injury frequency rates need a solid hours worked denominator. Teams often start from headcount and a standard schedule when payroll hours are not yet closed. This free calculator turns headcount into total hours for use in LTIFR, TRIFR, DART, and other rate tools.
Prefer actual hours from timekeeping when available. Exclude paid non-work time (vacation, holidays, sick leave) when your rate definition requires hours worked.
Hours Worked Calculator
Hours worked · Rate denominator
Convert headcount into total hours for LTIFR, TRIFR, DART, and other rates. Use payroll hours when you have them.
Formula: Hours = Headcount × Hours/Period × Periods
- Exclude paid leave when your rate uses hours actually worked.
- Keep contractor scope consistent with the KPI definition.
- Paste the total into LTIFR / TRIFR / DART as the hours denominator.
- Weekly schedule: Hours = Headcount × Hours/week × Weeks
- Daily schedule: Hours = Headcount × Hours/day × Days
- OSHA-style FTE year: Hours = FTE × 2,000
Frequently asked questions
Should contractors be included?
Follow your recording rules. Many corporate KPIs include contractor hours; OSHA logs have specific employee definitions — stay consistent with the rate you are publishing.
Why 2,000 hours per FTE?
OSHA’s 200,000-hour base equals 100 employees × 2,000 hours. It is a convenience figure, not proof that every FTE worked exactly 2,000 hours.
Can I mix overtime in?
Yes — if using a weekly model, raise hours/week to include average overtime, or paste payroll totals into the rate calculator instead.
Part-time workers?
Convert to FTE (e.g. two half-time workers ≈ 1 FTE) or enter actual headcount with their real average weekly hours.
