The Receivable Days Formula is a business metric commonly used to measure the average number of days it takes for customers to pay their outstanding debt. It can be calculated by dividing the value of a company’s accounts receivable during a certain period by its total sales during the same period, and then multiplying that figure by 360 days. This formula enables businesses to check the health of their finances in terms of customer payments, giving them insight into how efficiently they are managing their accounts receivable.