An attrition rate is a metric used to measure employees or customers lost over a period of time who are not replaced.
Human resources employees often use an attrition rate to determine the number of vacant or eliminated positions.
Formula to calculate attrition rate.
![Calculate Attrition Rate.](https://www.learntocalculate.com/wp-content/uploads/2020/08/attrition-rate..png)
Example:
Suppose a firm had 100 employees, 12 employees left and were not replaced. Calculate the attrition rate.
![Calculate Attrition Rate.](https://www.learntocalculate.com/wp-content/uploads/2020/08/attrition-rate.-2.png)
Therefore, the attrition rate is 12%.