Every business that hires employees has to deal with the fact that employees will always be coming and going. "Attrition" and "employee turnover" are both terms that companies use regarding this phenomenon. Companies and human resources departments tend to use both terms interchangeably, but in certain cases, recognizable distinctions may exist.

Causal Differentiation

One way in which human resources departments may view attrition and employee turnover as two different things is in regard to how they're caused. When employees leave a company, it may be due to reasons over which the company has no direct control — such as retirement due to old age — or it might be due to an avoidable reason, such as conflict in the workplace. Companies may differentiate between attrition and turnover by defining attrition as the number of employees who leave a company due to unavoidable reasons, and turnover as the total number of employees who leave a company, regardless of whether the reasons causing them to leave are avoidable or not.

Positive/Negative Differentiation

Another way of differentiating between employee turnover and attrition is to identify one as a positive force on the total number of employees and the other as a negative force. In this way, when a company wishes to measure fluctuations in its total number of employees for a certain period, it can do so by viewing attrition as the number of employees leaving the company during that period, and turnover as the number of employees hired during that period to replace those who have left.

Measuring Attrition and Turnover

To measure a company's attrition or turnover rate for a particular period, take the total number of employees hired or lost — but not both — within a certain time frame and divide that by the total number of employees in the company. Express this figure as a percentage.

Need for Differentiation

If you take the differentiation between the two into account, you may find that the numbers are slightly different. For instance, if a company has trouble finding replacements for employees it has lost, the total number of employees lost within a certain period — attrition — may be larger than the total number of employees hired, or turnover. Typically, though, the difference is miniscule, and even when it does exist, it's only a matter of time between losing a worker and finding someone to replace him.