HRIS

Staff Turnover and Absenteeism: How to Calculate

Turnover rate: leavers divided by average headcount, times 100. Absenteeism: days lost divided by days available. Formulas and a worked example here.

Updated September 23, 2026 Reviewed by Anudi Imesha, Customer Success Consultant, Humanised HR and Payroll 3 min read

On this page
  1. Choosing the period and the headcount base
  2. Turnover rate formula
  3. Voluntary vs involuntary turnover
  4. Absenteeism rate: days lost over days available
  5. What to exclude: approved leave, maternity, holidays
  6. Reading the numbers: when a rate is a problem
  7. Tracking both monthly without extra work
  8. Frequently asked questions
  9. What counts as a "leaver" in the turnover formula?
  10. Should I use start headcount, end headcount, or average?
  11. Does turnover include contract staff whose term simply ended?
  12. How do I calculate turnover for a whole year from monthly data?
  13. What is a normal absenteeism rate?
  14. Do I need software to calculate these, or can I use a spreadsheet?

Turnover rate: leavers in the period, divided by average headcount, times 100. Absenteeism rate: days lost to unplanned absence, divided by days available, times 100. Both work off records you should already have: headcount and leave history. See what employee records to keep, and for how long for the full list.

Choosing the period and the headcount base

Pick a period first: month, quarter or year. Then work out the average headcount for it:

Average headcount = (headcount at the start of the period + headcount at the end of the period) ÷ 2

Using the average, rather than just the start or end figure, smooths out hiring and leaving that happens mid-period.

Turnover rate formula

Turnover rate = (number who left in the period ÷ average headcount) × 100

Worked example, 40-person company, one quarter:

StepFigure
Staff at start of quarter40
Staff at end of quarter38
Left during the quarter4
Average headcount: (40 + 38) ÷ 239
Turnover rate: 4 ÷ 39 × 10010.3%

Voluntary vs involuntary turnover

Split your leavers into two groups before you calculate:

  • Voluntary. People who resigned.
  • Involuntary. People whose employment the business ended: dismissal, redundancy, or a contract that ran out.

A leaver with long service may also be due gratuity; see counting years of service for gratuity.

Run the same formula on each group separately, alongside the overall rate. Resignations point at pay, management or workload. Dismissals and ended contracts point at hiring.

Absenteeism rate: days lost over days available

Absenteeism rate = (unplanned absence-days in the period ÷ total available working days) × 100

Total available working days = number of employees × working days in the period

Worked example, same 40-person company, one month:

StepFigure
Employees40
Working days in the month22
Available days: 40 × 22880
Unplanned absence-days recorded18
Absenteeism rate: 18 ÷ 880 × 1002.05%

What to exclude: approved leave, maternity, holidays

Only unplanned absence goes in the numerator. Leave the following out:

  • Approved annual leave.
  • Approved casual leave.
  • Maternity leave.
  • Public and mercantile holidays.

These are entitled, planned time off, not attendance failures. Counting them as absenteeism inflates the rate.

Reading the numbers: when a rate is a problem

There is no fixed number that marks a “bad” rate for every business. The trend matters more. Is the rate rising month on month? Is it concentrated in one team or under one manager? A rate that keeps climbing is worth investigating, whatever the starting number.

Tracking both monthly without extra work

Both formulas run off two records you should already keep: headcount, and leave taken. If you log start dates, leaving dates and leave, no extra data collection is needed. The ETF R4 half-yearly return belongs in the same monthly review.

Do this automatically in Humanised. An employee management system holds the headcount and leave history these formulas need. It keeps start and leaving dates, and leave taken against each entitlement, in one record per employee.

This is general payroll guidance. Every case is different. For your own case, speak to a payroll practitioner or a lawyer.

Frequently asked questions

What counts as a “leaver” in the turnover formula?

Anyone whose employment ended in the period you are measuring, whether they resigned or were dismissed. Split voluntary and involuntary leavers for a clearer picture.

Should I use start headcount, end headcount, or average?

Average of the start and end figures. It corrects for hiring or leaving during the period itself.

Does turnover include contract staff whose term simply ended?

Include them as involuntary leavers if you are tracking that split. Whether to include them in the headline turnover figure at all is your own policy choice; state it consistently.

How do I calculate turnover for a whole year from monthly data?

Use the same formula with yearly figures. Total leavers for the year, divided by the average of the start-of-year and end-of-year headcount, times 100.

What is a normal absenteeism rate?

There is no fixed Sri Lankan benchmark. Track your own trend over several months instead of comparing to an outside number.

Do I need software to calculate these, or can I use a spreadsheet?

A spreadsheet works, provided your headcount and leave records are accurate and up to date. The formulas themselves need no special tool.

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