Definition
Attrition is leavers as a percentage of headcount over a period. Two accepted methods exist: leavers ÷ headcount at the start of the period, and leavers ÷ average headcount. The average method is more stable when headcount is growing or shrinking quickly.
Monthly rates are usually annualised. Multiplying by 12 is the quick method; compounding, 1 − (1 − monthly)^12, is more realistic because each month's leavers come from an already-reduced population. A 4.5% monthly rate is 54% simple but roughly 42% compounded.
The headline number is nearly useless without a split: voluntary versus involuntary, early-life versus tenured, controllable versus uncontrollable.
Why it matters
- Attrition sets your recruitment and training pipeline. High attrition means a permanent flow of low-tenure agents with higher AHT and lower quality.
- Long-range capacity plans that ignore attrition overstate available FTE within two or three months.
- Early-life attrition points at recruitment and training; tenured attrition points at management, progression and pay.
Get new WFM tools first
One short email when a new calculator, template or article goes live. No spam.