Hi pandurang,
Attrition rate = No. of resignation / Available manpower *100
Example- If 1st of any of the month the Manpower is 200, during that particular month 10 employees Joined whereas 5 resigned, so at the end of the month the available manpower would be
Available Manpower = 200+10-5 = 205
Attrition Rate = 5 / 205 *100
Hope it must have helped you to understand the same...
Regards,
Amit Seth.