Days Sales Outstanding (DSO) Calculator
Calculate Days Sales Outstanding to measure how long it takes to collect payment after a sale.
Enter AR, net sales, and period length.
DSO measures how many days, on average, it takes your business to collect cash after a sale. A company with $500,000 in accounts receivable and $5,000,000 in annual credit sales has a DSO of about 36 days — customers are paying roughly five weeks after invoicing.
The formula:
DSO = (Accounts Receivable / Net Credit Sales) x Days
“Days” is the period you are measuring: 30, 90, or 365. Most analysts use 365 for annual reporting or 90 for a quarterly snapshot.
What counts as a good DSO? It depends entirely on your payment terms. If you invoice net-30, a DSO of 32 is fine. A DSO of 65 on net-30 terms means customers are regularly paying late, and cash flow will suffer before you notice it on the income statement. Manufacturing and wholesale typically run 40-60 days. Software companies with annual upfront contracts often show very low DSOs.
High DSO is not always the customer’s fault. Invoices with errors, disputes over deliverables, or billing that happens weeks after delivery all inflate DSO. The first place to look when DSO climbs is internal billing processes, not collections.
One thing beginners miss: DSO only applies to credit sales. If 30% of your revenue is cash or card transactions, exclude those from the denominator. Mixing cash and credit sales understates the real collection lag.
DSO is one of three cash conversion cycle metrics. Pair it with Days Inventory Outstanding (DIO) and Days Payable Outstanding (DPO) for the full picture of how quickly your business converts operations into cash.
CCC = DIO + DSO - DPO
A lower DSO shortens the cycle directly. Companies obsessed with working capital treat DSO as a monthly KPI, not a quarterly afterthought.