calculate attrition

To calculate attrition, divide the number of departures in a period by the average headcount for that period, then express it as a rate.

The arithmetic is not the difficult part. Four errors account for most bad figures.

Counting internal moves as departures, which inflates the rate and hides where the genuine loss is. Annualising a short period without adjusting for it, so one quiet quarter becomes an implausible year. Including casuals in the departures but leaving them out of the headcount. And quietly changing the method between periods, which makes the whole trend meaningless.

Calculate it monthly rather than yearly if you can. An annual figure arrives far too late to act on, and the pattern within the year is almost always the more informative part of it.

The Fair Work Ombudsman covers record-keeping requirements. This is general information rather than legal advice, and obligations vary by state and territory.

See Sentrient’s HR management system and records management software.