There are so many different formulae for Attrition. The one which I followed for Monthly Attrition Calculation is as follow:
Average: Opening Headcount+Closing Headcount/2
Attrition Rate: No. of employees left / Average Headcount * 100
Now, the confusion is that for monthly attrition, the average headcount should be as per above formula or it should be: Opng Headcount + Closing Headcount / 12
Also, I've seen some post which mentions below:
Average Headcount : if monthly : divide by 2
if quarterly : divide by 4
if yearly : don't divide
whereas, in some post it mentions that for yearly calculation, divide by 12.
Please let me know what is the correct formulae for monthly and yearly attrition???