There are three ways to calculate bonuses for employees: Sales commission: This is as easy as multiplying the commission percentage by the total sales. To determine a fair commission percentage, consider factors such as the employee’s involvement in the sales process, the value of their role, and the price of your product. Percent of salary: When dealing with full-time employees, you can offer bonuses based on their salary. Simply multiply the end-of-the-year bonus percentage by their salary. Sign-on bonus: This is usually a flat rate lump sum fee, but if you intend to pay it in installments, divide the amount by the number of desired installments. You should also remember that bonuses are taxable.