What term describes the number or percentage of employees that leave and need to be replaced?

The term that accurately describes the number or percentage of employees who leave and need to be replaced is "employee turnover." This concept encompasses all instances in which employees depart from an organization, whether voluntarily or involuntarily, and it highlights the need for employers to replace those individuals to maintain operational efficiency. High turnover can indicate potential issues within a workplace, such as dissatisfaction, poor management practices, or inadequate training, and organizations often monitor turnover rates to implement strategies for improvement.

Employee retention refers to the strategies and practices an organization uses to keep its employees and reduce turnover. While retention focuses on keeping staff engaged and satisfied, it is not a direct measurement of the employees leaving. Workforce fluctuation suggests variations in employee numbers but lacks the specificity of tracking exits or replacements. The term "staff replacement rate" is not commonly used in industry standards and lacks the broad understanding associated with turnover. Therefore, employee turnover is the most precise and recognized term for this phenomenon.