Attrition measures departures as a percentage of headcount, usually annualised. It's split into voluntary (resignations - the worrying kind) and involuntary (exits initiated by the employer), and often examined as regretted vs non-regretted. High voluntary/regretted attrition is expensive (rehiring, lost knowledge) and a signal about pay, management or engagement - where benefits and wellbeing play a retention role.
In India
Indian IT/ITeS saw very high attrition in recent boom years. Benefits differentiation (parental cover, wellbeing, flexibility) is one lever CHROs use to defend retention alongside pay.
In practice
Annual attrition = (leavers in year ÷ average headcount) × 100. 60 leavers over an average 500 headcount = 12%. HR digs into whether the regretted share is rising, and in which teams.