Attrition Formula [Thread 267623]

Dear All,
Attrition Calculation
No of employee left = X
No. of Employees Joined = A
Opening headcount during the period= B
Average Headcount (C)= A+B/2
Attrition Rate= X/C *100
If this formula correct
Regards,
Amrita

Pls find the formula that we use.
Annual attrition rate: Total number of resigned employee in past 12 months / (headcount at month 1-Jan + headcount at month 12-DEC)/2
Monthly attrition rate: total number of resignees in a month/(headcount in the begining of the mth + headcount at the end of the mth)/2
Opening Balance = 415
New addition = 115
Attrition = 129
Attrition formula to % = 129/472.5*100
= 27.3%