its not a question that can be answered unless you state the pwm period and the pwm resolution required along with fosc
PWM Period = PRx+ 1  4 TOSC (TMRx Prescale Value
Pulse Width = CCPRxL:CCPxCON<5:4> T OSC (TMRx Prescale Value)
I cant get the duty cycle formula to paste into this properly , its in the data sheet