Is the 12 week FMLA leave considered to be 12 weeks x 40 hours per week = 480 hours? So if an employee is working 50 hours work weeks, is the FMLA period 9.5 weeks? Is the 12 week FMLA leave considered to be 12 weeks x 40 hours per week = 480 hours? So if an employee is working 50 hours work weeks, is the FMLA period 9.5 weeks? No, you must calculate actual work replacement. This means that an employee who works 50 hours per week will have up to 600 hours of intermittent leave available. If the employee works 32 hours per week, then the calculation is 32 hours per week x 12 weeks = 384 hours. Yes, the employee is allowed 480 hours of FMLA leave only