Attrition rate or the churn rate is the rate at which the employees leave the company. Mathematically, it is the number of employees that have left a company divided by the average number of employees in a given time period, and then multiplying by 100 to get a percentage. Attrition is good only until it is 10%. Higher attrition rates may imply that employees are unsatisfied with their work and that can require further investigation into improving the overall work culture.