What it means
The word covers two related measures that are often muddled in meetings. Employee attrition counts people leaving the organisation, while customer attrition, more commonly called churn, counts accounts that stop buying.
Both answer the same question: how much of what you had at the start has quietly drained away. The calculation divides the number of leavers during a period by the average number in the population over that same period.
Using an average rather than the opening or closing figure matters when a business is growing or shrinking quickly, because otherwise the rate flatters or punishes you for reasons unrelated to retention. Most organisations report attrition monthly and quote it on an annualised basis.
Attrition matters commercially because the cost of a replacement is much larger than most managers assume. Recruitment fees, interview time, onboarding, and the months before a new joiner reaches full productivity commonly add up to somewhere between 30% and 100% of an annual salary.
That means a single percentage point of attrition on a large team can be worth six figures. Headline attrition is nearly useless on its own, which is why good reporting splits it up.
Regretted attrition covers people the organisation wanted to keep, first-year attrition points at recruitment or onboarding problems, and attrition by manager or team usually tells you more than any company-wide number. A stable 12% overall figure can hide a team losing half its engineers.
On the customer side there are two versions worth separating. Logo attrition counts departing accounts regardless of size, while revenue attrition weights each departure by what it was worth, and the two can point in opposite directions.
Losing many tiny accounts while retaining the large ones is a very different problem from the reverse. The final nuance is that zero attrition is not the goal.
Some turnover brings in new skills, creates promotion opportunities and moves out poor performers, so the sensible target is a rate in line with a comparable industry benchmark. What should worry a board is a rate that is rising, concentrated in one area, or made up of the people you least wanted to lose.
In practice
Real-world examples.
Example
A contact centre with 400 seats runs at 38% annual attrition, well above the 25% its competitors report. Analysis shows two thirds of leavers go within their first ninety days, so the operations director redesigns induction and pairs new starters with a mentor. Attrition in the first-year cohort falls by a third over the following two quarters.
Example
A gym chain loses 4% of its members every month, which compounds to roughly 40% over a year. The marketing team had been spending its entire budget on acquisition, so the chief executive shifts a quarter of it into a member engagement programme. Monthly attrition drops to 3.1% and membership grows without any change in advertising spend.
Example
A consultancy notices that attrition among second-year analysts has reached 30% while the firm-wide figure sits at a comfortable 14%. Exit interviews point to unclear progression rather than pay. The firm publishes a promotion framework and the second-year rate halves within a year.
Formula
Calculation
Attrition Rate = Leavers in the Period / Average Headcount in the Period x 100
Average Headcount = (Opening Headcount + Closing Headcount) / 2
Worked example. Marlowe Freight begins the year with 240 employees and ends with 260, and 26 people leave during the year.
Average headcount = (240 + 260) / 2 = 250.
Annual attrition rate = 26 / 250 x 100 = 10.4%.
To put a cost on that, the human resources team estimates replacement cost at 40% of an average salary of $70,000, which is $70,000 x 40% = $28,000 per leaver. Total replacement cost for the year = 26 x $28,000 = $728,000.
If the business could bring attrition down to 7%, leavers would fall to 250 x 7% = 17.5, rounded to 18 people. That saves 26 - 18 = 8 replacements, worth 8 x $28,000 = $224,000 a year, which comfortably funds a retention programme.Case study
Seen in the real world.
Marlowe Freight is an illustrative, fictional regional haulier used here to show how an attrition number turns into a decision. Its board had been looking at a single company-wide figure of 10.4% and treating it as healthy, since the industry benchmark sat around 12%. Nobody questioned it for two years.
When the finance team finally split the number by depot, it found that three of the eleven depots were running above 20% while the rest sat under 7%. Those three depots also accounted for most of the overtime spend and nearly all of the late deliveries, because agency drivers were covering gaps at a premium.
In this fictional case the intervention was narrow rather than company-wide: new depot managers at two sites, revised shift patterns at the third, and a modest retention bonus for drivers passing eighteen months. Attrition at the three depots fell to 11% over the following year and overtime spend dropped by roughly $310,000, which is a far better outcome than an expensive scheme applied everywhere.
Watch out
Common mistakes.
- Dividing leavers by opening headcount instead of average headcount. In a fast-growing team this understates attrition badly, because the denominator ignores everyone who joined during the period.
- Reporting a single company-wide rate and stopping there. Attrition is nearly always concentrated in specific teams, tenures or managers, and the average hides exactly the detail you need.
- Treating all attrition as bad. Losing people who were not performing or who were blocking progression can improve a team, which is why regretted attrition is the figure worth tracking.
Questions
People also ask.
What is a good attrition rate?
It depends entirely on the sector, since professional services and hospitality live with very different norms, so compare against a relevant benchmark rather than an absolute target.
What is the difference between attrition and turnover?
They are often used interchangeably, though some organisations reserve attrition for roles that are not backfilled and turnover for all departures.
How does customer attrition affect valuation?
Directly, because lower attrition raises customer lifetime value and makes recurring revenue more predictable, which investors reward with a higher multiple.
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