Attrition rate

How do you calculate attrition rate?

Divide the number of departures in a period by the average headcount for that period, then multiply by 100. Average headcount is usually taken as headcount at the start plus headcount at the end, divided by two. Eighteen departures against an average headcount of 120 is a 15% annual attrition rate.

Most teams also split the number into voluntary and involuntary attrition, and the sharper ones track regretted attrition separately, because losing people you wanted to keep is a different problem to managed exits.

What is the difference between attrition and turnover?

In everyday HR use the two are close to interchangeable, and the formula is the same. Where a distinction is drawn, attrition usually refers to departures the organisation does not backfill (a role retired with the person), while turnover covers all separations, replaced or not. If you report both, define both, because your CFO's definition may not match yours.

What is a healthy attrition rate?

The Australian average sits around 16% a year (AHRI). Against that, low single digits can signal a stagnating workforce as easily as a happy one, and anything sustained above the mid-twenties usually costs more than it looks, because every departure carries recruitment, ramp-up and lost-knowledge costs. The rate that matters most is attrition among your top performers, which no company average will show you.