A/R Days Ratio is a financial ratio used to measure the average number of days it takes for a company’s accounts receivable to be paid. A/R stands for “accounts receivable,” which are the amounts owed by customers who have purchased products or services from a business but haven’t yet paid for them, and it refers to the number of days that these amounts remain outstanding. The A/R Days Ratio is calculated by dividing 365 by the current ratio. Although there isn’t a hard and fast rule about what constitutes an acceptable amount, since there are different industries with different operating procedures, businesses should typically have an A/R Days Ratio of less than 60 days.