What is attrition rate?
Attrition rate is the number of employees who leave during a period divided by the average headcount over that period, expressed as a percentage. Monthly attrition = leavers in the month / average headcount x 100. Annualized attrition multiplies the monthly rate by 12, which is the same as dividing a year of leavers by the year's average headcount.
In a call center each leaver is a hire, a block of training hours and a ramp period at lower productivity. ContactBabel's US guide also lists the knock-on effects on first-time resolution, transfer rates, queue time and call length, and on the morale of the agents who stay. The calculator gives you the monthly figure you can track and the annual figure you can compare with published benchmarks.
The attrition rate formula
ContactBabel uses the same definition for its US benchmark: the total number of agents leaving in a 12-month period divided by the average number of occupants over the same period. It counts voluntary and involuntary leavers and leaves out internal transfers (ContactBabel, The 2024 US Contact Center Decision-Makers' Guide). Follow the same rules and your number is comparable with theirs.
Two end points are enough when headcount is steady. If it swings inside the period, for example because a training class starts mid-month, average the weekly or daily headcount instead.
Annualized attrition vs 12-month cohort loss
The two annual numbers answer different questions. Annualized attrition counts leavers per seat per year, including replacements who leave in turn, so on a high-churn floor it can pass 100 percent. The 12-month cohort loss is the share of today's agents who will have left a year from now if the monthly rate holds, which can never pass 100 percent. Use the annualized rate for benchmarking, because published figures use that definition, and the cohort figure when you want to know how much of your current team you will still have next year.
Worked example
A team starts the month with 60 agents and ends it with 64, and 2 agents leave during the month. Average headcount is (60 + 64) / 2 = 62, so monthly attrition is 2 / 62 = 3.2 percent. Annualized, that is 2 / 62 x 12 = 38.7 percent, or about 24 leavers a year on a 62-seat team. If the monthly rate holds, 1 - (1 - 2/62)^12 = 32.5 percent of today's agents will have left within 12 months.
Those are the calculator's default inputs and they are illustrative. For a quarter, enter the quarter's leavers with 3 in the months field: 18 leavers on a team that averages 195 agents over three months gives 9.2 percent for the quarter, 3.1 percent a month and 36.9 percent annualized.
Call center attrition benchmarks
ContactBabel's 2024 US Contact Center Decision-Makers' Guide reports a mean annual agent attrition rate of 31 percent and a median of 24 percent at year-end 2023, down from 36 and 28 percent at year-end 2021. The spread is wide: 25 percent of respondents reported attrition of 10 percent or less, while 33 percent were above 30 percent (ContactBabel, The 2024 US Contact Center Decision-Makers' Guide).
| Year-end | Mean annual agent attrition | Median annual agent attrition |
|---|---|---|
| 2021 | 36% | 28% |
| 2022 | 33% | 20% |
| 2023 | 31% | 24% |
Source: ContactBabel, The 2024 US Contact Center Decision-Makers' Guide (16th edition), Figure 2. US contact centers.
Compare your annualized rate, not your monthly one, with these figures. For views by vertical and delivery geography, use the attrition benchmark tool.
What attrition costs
The rate is the start of the sum. Each leaver sets off a hire, training time and weeks at below-target productivity, and the turnover cost calculator prices that from your own wage, rate and team size. Churn also changes staffing: new agents often take longer per call, and open seats push the rest of the team toward higher occupancy. Check both with the AHT calculator and the Erlang calculator.
FAQ
What is attrition rate?
Attrition rate is the number of employees who leave during a period divided by the average headcount over that period, expressed as a percentage. A team that averages 62 agents in a month and loses 2 of them has a monthly attrition rate of 2 / 62 = 3.2 percent.
How do you calculate monthly attrition rate?
Divide the number of leavers in the month by the average headcount for the month and multiply by 100. Average headcount is the headcount at the start plus the headcount at the end, divided by 2. With 60 agents at the start, 64 at the end and 2 leavers, the monthly rate is 2 / 62 = 3.2 percent.
How do you annualize a monthly attrition rate?
Multiply the monthly rate by 12. A 3.2 percent monthly rate (2 leavers on an average of 62) annualizes to 2 / 62 x 12 = 38.7 percent. That matches the standard annual definition, a year of leavers divided by the year's average headcount. If you want the share of today's team that will be gone in a year instead, use 1 - (1 - monthly rate)^12, which gives 32.5 percent in the same example.
What is a good attrition rate for a call center?
ContactBabel's 2024 US Contact Center Decision-Makers' Guide reports a mean annual agent attrition rate of 31 percent and a median of 24 percent at year-end 2023. The spread is wide: 25 percent of respondents reported 10 percent or less, and 33 percent were above 30 percent. Compare your annualized rate with those figures, not your monthly one.
Is attrition rate the same as turnover rate?
Many teams use the two terms for the same calculation, leavers divided by average headcount. Some reserve turnover for leavers who are replaced and attrition for roles left unfilled. Whichever you use, state the definition next to the number so it can be compared.
Should internal transfers count as attrition?
Usually not. ContactBabel's benchmark counts agents who leave the contact center, voluntary or involuntary, and excludes transfers elsewhere within the organization. Counting transfers makes your rate look worse than a benchmark built on the same definition.
Keep going
Price what this churn costs with the turnover cost calculator and compare it by vertical in the attrition benchmark tool. See how open seats and new-hire handle times change your staffing in the Erlang C calculator, the AHT calculator and the shrinkage calculator. Score the rest of your KPIs in the call center KPI benchmarks, read the call center attrition guide, or browse every free tool on the tools hub.