Attrition rate
The share of your people who leave in a year.
01 What it is
Why anyone looks at this number
The share of your people who leave in a year.
Every leaver costs recruitment, ramp-up time and lost knowledge. In operations it also shows up directly in quality and safety numbers.
02 The formula
How it is worked out
Attrition rate = leavers_in_period ÷ average_headcount grain : year × function × site unit : percentage per year source : HR information system
Split voluntary from involuntary. They have opposite meanings, and reporting them together makes a restructuring look like a retention crisis.
03 Worked example
The same number, with real inputs
| Voluntary leavers | 38 |
| Average headcount | 265 |
| Calculation | 38 ÷ 265 |
| Result | 14.3% |
Roughly one in seven. If 40% of leavers had under a year of service, the problem is at the front door, not in retention.
04 What moves it
Four things that actually change this number
Manager quality
The most consistent predictor there is.
Pay position
Where you sit against the local market, not the national one.
Progression
Whether people can see a next step.
Onboarding
First-year attrition is usually a hiring or induction problem.
05 Where the number lives
The system, the record and the fields
| System of record | Key record | Fields you need |
|---|---|---|
| HR information system | Employee and Position | hire_date, leave_date, reason, voluntary_flag, manager, location |
Split voluntary from involuntary. They have opposite meanings, and reporting them together makes a restructuring look like a retention crisis.
06 How it goes wrong
Three ways this metric misleads people
One rate for the whole business
Site and function rates differ enormously and the average hides both extremes.
Fix: Report by function, site and manager.Ignoring regretted versus not
Losing low performers is not the same as losing your best people.
Fix: Track regretted attrition separately.No first-year split
Early leavers mean a different problem from long-tenure leavers.
Fix: Split by tenure band, starting with under twelve months.08 Questions
Frequently asked
What is a healthy attrition rate?
Some turnover is healthy; zero is a warning sign of its own. Compare to your local labour market and watch regretted attrition rather than the headline.
How do we cost a leaver?
Recruitment cost plus the ramp-up gap: the months before a replacement performs at full output. In skilled roles the ramp-up usually exceeds the recruitment cost several times over.
One definition, everywhere it is used
SCIKIQ stores this metric once and serves it to every dashboard, board pack and agent that asks.