Two or more other employees
Generally a total of 80 employee hours of work. One full-time (40 hours per week) and two half-time employees (20 hours per week), for example, are equivalent to two full-time employees. Four half-time employees are also equivalent.
In industries where the established standard defining full-time schedules is 37 1/2 hours or 35 hours per week, two or more other employees may be defined as 75 or 70 hours, respectively.
Source: U.S. Department of Labor