The Days Of Sales Outstanding (DSO) Formula is a common measure of how quickly a company collects money from its customers. It compares the amount of debt owed to a business against the average daily sales that generate that debt. The higher the DSO Number, the longer it takes the company to receive cash from its customers. To calculate this number, simply divide the sum of all customer receivables by the total net credit sales for a specific period, and multiply by the number of days in that period. A lower DSO you indicate better collection efforts and improved performance. Knowing your DSO can help you maximize cash flow and make sure that you get paid for the products or services you provide.