Part of the HR metrics hub — the analytics layer of the hiring funnel. It connects to employer operations for planning and to the staffing layer when you need to bridge a gap.
What it measures
Attrition rate, like turnover, expresses separations during a period as a share of average headcount. The common distinction many teams draw is that "attrition" highlights a reduction in roles — positions that are left open — while "turnover" covers all departures whether or not they are backfilled.
Because the words are used loosely, the metric is only meaningful once you state your own definition and keep it consistent.
Why it matters
Attrition framed as un-backfilled departures connects directly to capacity: each unfilled role is work that must be absorbed or dropped. Tracking it helps you see when natural reduction is shrinking a team faster than planned.
It also informs decisions about where to consolidate, restructure or deliberately not replace a role.
Formula
(Attrition departures ÷ Average number of employees) × 100
Identical in shape to the turnover formula — the difference is in how you define the numerator. State it explicitly.
Worked example: If 5 departures within your attrition definition occurred against an average headcount of 100, attrition is (5 ÷ 100) × 100 = 5% for the period.
Calculate it instantly
Use the free employee turnover rate calculator — it runs in your browser, with no signup and nothing stored.
Inputs you need
- Departures that fit your attrition definition
- Average headcount for the period
- A documented definition that distinguishes attrition from turnover
- A consistent period
How to read it
Because attrition and turnover share a formula, the interpretation hinges on definition. Make clear whether you are counting all departures or only un-backfilled ones, and never compare figures built on different definitions.
Read attrition alongside headcount growth and capacity metrics to see whether reduction is intentional or eroding capacity.
Common mistakes
- Using "attrition" and "turnover" interchangeably without defining either.
- Comparing your attrition to figures elsewhere that use a different definition.
- Ignoring whether departures were backfilled.
- Treating all attrition as negative when some may be planned.
Operational considerations
- Write down exactly what your attrition figure includes and how it differs from turnover.
- Tag departures by whether the role is being backfilled.
- Review attrition with capacity and headcount-growth metrics, not alone.
- Distinguish planned reduction from unplanned loss in reporting.
Use this metric inside the operating cadence: plan with workforce planning and headcount planning, anticipate demand with hiring forecasting, and check it against workforce capacity planning.
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