To calculate the income tax of an employee, you need to consider various factors such as the employee's salary, deductions, exemptions, and tax rates applicable in the specific jurisdiction. It is important to accurately calculate the income tax to ensure compliance with tax laws and regulations. Employers often use payroll software or engage tax professionals to handle the calculation of income tax for their employees. By understanding the tax rules and using the right tools, employers can accurately determine the income tax obligations for their employees.