Attrition Rate Calculator
Calculate your organization's attrition rate (turnover rate), retention rate, and average headcount for any given period.
Formulas Used
Average Headcount = (Employees at Start + Employees at End) ÷ 2
Attrition Rate (%) = (Employees Who Left ÷ Average Headcount) × 100
Retention Rate (%) = 100 − Attrition Rate (%)
Assumptions & References
- The average headcount method (start + end ÷ 2) smooths out fluctuations during the period and is the most widely accepted approach for attrition calculations.
- Employees who left includes all separations — voluntary (resignations, retirements) and involuntary (layoffs, terminations) — unless you wish to calculate voluntary attrition only.
- Attrition rate is typically measured monthly, quarterly, or annually. Annualizing a monthly rate: multiply monthly rate by 12.
- A healthy attrition rate varies by industry; a commonly cited benchmark is 10–15% annually across most sectors (SHRM, 2023).
- Formula reference: Society for Human Resource Management (SHRM) — Human Capital Benchmarking Report.
- New hires added during the period are reflected in the end headcount but are not counted as "employees who left."