How to Calculate Employee Attrition Rate (with Examples)

Employee attrition rate is the share of employees who leave an organisation over a period. It is one of the first numbers a founder or board asks HR for, and one of the most frequently miscalculated. Different teams use different formulas, include or exclude interns and contract staff inconsistently, or compare a monthly number with someone else's annual one. This guide shows how to calculate attrition rate correctly, with monthly and annual formulas, worked examples, the splits that make the number useful and how to turn analysis into action. The aim is a number you can defend and compare over time.

Attrition, Turnover and Retention: Definitions

These terms are used loosely in India, so define them in your HR reports:

Term	Meaning in this guide
Attrition	Employees leaving the organisation for any reason during a period
Voluntary attrition	Employees who chose to leave, such as resignations
Involuntary attrition	Exits initiated by the employer, such as termination or layoffs
Regretted attrition	Voluntary exits of employees the company wanted to keep
Early attrition	Exits within a set period after joining, commonly 90 days or one year
Retention rate	Share of employees present at the start of a period who are still employed at the end

Some organisations use "turnover" to mean exits that are replaced and "attrition" for exits that are not. Whatever you choose, write it down and use it consistently.

The Basic Attrition Rate Formula

Attrition rate (%) = (Number of separations during the period / Average headcount during the period) x 100

Average headcount = (Headcount at start of period + Headcount at end of period) / 2

For more accuracy in fast-growing companies, use the average of monthly headcounts instead of just the start and end figures.

Worked Example: Monthly Attrition

A hypothetical company has 200 employees on 1 March and 210 on 31 March. Eight employees left during March.

Average headcount = (200 + 210) / 2 = 205
Monthly attrition = 8 / 205 x 100 = 3.9 percent

Monthly numbers look small and fluctuate, so most companies report them alongside an annual or annualised figure.

Worked Example: Annual Attrition

Over the financial year, the same company had these figures:

Month	Opening headcount	Joiners	Separations	Closing headcount
April	180	8	4	184
May	184	6	5	185
June	185	9	6	188
July	188	7	3	192
August	192	5	4	193
September	193	6	5	194
October	194	10	6	198
November	198	4	3	199
December	199	5	4	200
January	200	6	5	201
February	201	7	8	200
March	200	18	8	210

Total separations = 61
Average of monthly closing headcounts is about 195
Annual attrition = 61 / 195 x 100 = 31.3 percent

Using only start and end headcount, (180 + 210) / 2 = 195 gives the same answer here, but in companies with seasonal hiring the two methods can differ noticeably.

Annualising a Monthly or Quarterly Rate

If you have only part of a year, you can estimate an annual rate:

Annualised attrition = (Separations year to date / Average headcount year to date) x (12 / Months elapsed) x 100

Example: 30 separations in the first six months with average headcount of 190 gives (30 / 190) x (12 / 6) x 100 = 31.6 percent annualised. Label it clearly as annualised; it is a projection.

Splits That Make Attrition Useful

A single company-wide number hides what matters. Calculate attrition for each of these splits:

Voluntary vs involuntary

A company with 30 percent attrition, mostly involuntary because of a restructuring, has a different problem from one with 30 percent voluntary resignations.

Regretted vs non-regretted

Ask managers to classify each voluntary exit at the time it happens. Losing low performers is not the same as losing your best engineer.

By tenure

Tenure at exit	Separations	Share
0 to 3 months	14	23%
3 to 12 months	19	31%
1 to 3 years	20	33%
3 years and above	8	13%

In this hypothetical example, more than half of exits happen in the first year. That points to hiring, expectation setting or onboarding issues rather than pay or career growth.

By department, location, manager and role

Attrition concentrated in one team or under one manager is often the most actionable finding. Be careful with small numbers: two exits in a team of six is 33 percent but may not indicate a pattern.

By performance rating

If top-rated employees leave at a higher rate than average performers, your rewards are not differentiating enough.

By exit reason

Use exit interview data, categorised consistently: compensation, career growth, manager, workload, relocation, higher studies, health, and so on. Our offboarding checklist covers how to run exit interviews that produce usable data.

Early Attrition: The Number Most Companies Miss

Early attrition rate = (Joiners who left within 90 days / Total joiners in the cohort) x 100

Track by joining cohort. If 40 people joined between April and June and 7 left within 90 days of joining, 90-day attrition for that cohort is 17.5 percent. Early attrition is expensive because you pay recruitment and training costs and get little productive time. It usually reflects mismatched expectations at hiring or a weak first month.

Retention Rate

Retention rate (%) = (Employees at start who are still employed at end / Employees at start) x 100

Retention looks only at people who were already there, so it is not distorted by new hiring. If 180 employees were present on 1 April and 140 of those were still there on 31 March, retention is 77.8 percent.

Common Calculation Mistakes

Mixing employee types. Decide whether interns, trainees, fixed-term and contract staff are included, and report them separately if needed.
Counting internal transfers as exits. They are not.
Using end-of-period headcount only. This understates attrition in growing companies.
Comparing monthly with annual figures. Always label the period.
Counting exit date inconsistently. Use the last working day, not the resignation date.
Ignoring small sample sizes. Report counts alongside percentages for small groups.

From Numbers to Action

Find the hotspots. Which segments have the highest regretted attrition?
Understand why. Combine exit interview themes, engagement survey results and manager input.
Pick two or three interventions, such as better onboarding for early attrition, pay corrections for a role that is below market, or manager coaching for a team with high exits.
Set a target and track monthly.
Use stay interviews with high performers to learn what keeps them before they leave.

Engagement data is an early warning signal for attrition. Our guide to engagement survey questions and eNPS explains how to collect it.

Presenting Attrition to Leadership

Leaders need a clear, consistent view rather than a spreadsheet dump. A one-page monthly attrition summary might include:

Annualised attrition and the trend over the last 12 months, with voluntary and involuntary shown separately.
Regretted attrition count and names of roles affected, without personal details beyond what is needed.
Top three departments or locations by voluntary attrition, with counts.
Early attrition for the latest joining cohort.
Top exit reasons this quarter from exit interviews.
Actions under way and their status.

Keep definitions in a footnote on every report so nobody compares your figure with a differently calculated number from a news article or another company. If you benchmark externally, make sure the comparison uses the same definition, industry and employee type.

Setting Up Your Data So the Numbers Are Reliable

Attrition analysis is only as good as the employee records behind it. Before your first report, make sure every separated employee record has a last working day, an exit type (resignation, termination, retirement, end of contract, death), a reason code from a fixed list, and a regretted or non-regretted flag set by the manager. Joiners need accurate joining dates, department, location and manager so segments are correct. Rehires should be linked to their earlier records, not created as new people. A small amount of discipline at exit time saves hours of cleaning later.

Estimating the Cost of Attrition

Putting a rough cost on attrition helps leaders weigh retention investments. A simple estimate per exit includes recruitment costs, time for interviewers, onboarding and training time, lost productivity during the vacancy and while the new joiner ramps up, and any agency fees. For many roles in India, a commonly used rule of thumb places this somewhere between a few months' and a year's salary, but your own numbers are more persuasive than a rule of thumb. Pick two or three common roles and calculate the cost with your finance team.

Frequently Asked Questions

What is a good attrition rate?

It varies widely by industry, role and location. Compare with your own history and with credible industry benchmarks for similar roles, and focus on regretted and early attrition rather than the overall number.

Should involuntary exits be included in attrition?

Include them in total attrition but always report voluntary and involuntary separately.

How do I calculate monthly attrition rate?

Divide separations in the month by average headcount for the month and multiply by 100.

What is the difference between attrition and retention?

Attrition measures exits relative to average headcount. Retention measures how many of the employees present at the start of a period are still there at the end.

Should contract workers be included?

Report them separately. Mixing them with permanent staff makes trends hard to interpret.

Track Attrition Automatically

Fininvo HRMS includes headcount analytics, attrition analysis, custom dashboards and scheduled reports, built on the employee records and exit data already in the system. Explore HR analytics, offboarding or pricing.