Days Sales Outstanding (DSO)

Days sales outstanding (DSO) measures how long, on average, revenue sits in receivables before becoming cash. The standard calculation divides ending accounts receivable by credit sales for a period and multiplies by the number of days in the period. A company on net 30 terms with a DSO of 42 is collecting, on average, 12 days late; every day of DSO on $100 million of annual credit sales represents roughly $274,000 of cash trapped in receivables.

DSO is the headline metric of AR performance, and it rewards careful handling. Because the standard formula divides by sales, a strong sales month mechanically lowers DSO even if collections did not improve, and a weak month raises it. Variants address this: best possible DSO computes the floor implied by terms alone, and the countback (or exhaust) method matches receivables against the specific months of sales that generated them, giving a truer read when sales are volatile or seasonal.

Treat DSO as a trend and a decomposition, not a single number. The useful questions are: how does DSO compare to the weighted-average terms we actually grant (the gap is pure collection and dispute slippage), how is it trending over 6 to 12 months, and how does it break down by business unit, customer segment, and dispute status? Benchmarking against industry peers is directionally useful, but terms mix differs so much between industries that internal trend and the terms gap are the more actionable comparisons.