Attrition Rate Calculator

Attrition is the rate at which people leave your operation over a period. In contact centres it is the number that drives recruitment plans, training pipeline sizing and long-range capacity plans, because every leaver is a seat you must refill and re-train before it becomes productive again.

The two methods

• Start method: leavers ÷ headcount at start of period × 100. Simple and common. It overstates attrition in a fast-growing site, because new joiners are absent from the denominator.
• Average method: leavers ÷ average headcount × 100. Average headcount is normally (start + end) ÷ 2, or the mean of daily headcount. More stable when your headcount is moving, and the method most WFM teams prefer.

Annualising a monthly rate

Two conventions exist, and they disagree. Multiplying by 12 is the quick version and assumes a fresh, full population every month. Compounding , 1 − (1 − monthly rate)^12, reflects that each month's leavers come from a population already reduced by earlier losses, so it always produces the lower and more realistic number. A 4.5% monthly rate is 54% simple but about 42% compounded. Always state which one you used.

Split the number before you act on it

• Voluntary vs involuntary, resignations and dismissals need entirely different fixes.
• Early-life vs tenured, leavers inside 90 days point at recruitment or training; leavers after a year point at progression and management.
• Controllable vs uncontrollable, relocation and study are not a management failure; pay and rostering are.

For planning, convert attrition into a monthly replacement requirement, then add training lead time. If your annualised attrition is 40% on a 400-seat operation, you are hiring and onboarding roughly 13 people a month just to stand still, and your occupancy and shrinkage numbers are the leading indicators of whether that figure will rise.