How do I calculate the ''total hours worked'' on my annual summary when I have both hourly and temporary workers?

To calculate the total hours worked by all employees, include the hours worked by salaried, hourly, part-time and seasonal workers, as well as hours worked by other workers you supervise (e.g., workers supplied by a temporary help service). Do not include vacation, sick leave, holidays, or any other non-work time even if employees were paid for it. If your establishment keeps records of only the hours paid or if you have employees who are not paid by the hour, you must estimate the hours that the employees actually worked.