How to Calculate Days Sales Outstanding (DSO)

Days Sales Outstanding (DSO) measures the average number of days it takes your business to collect payment after a sale. It turns your accounts receivable balance into a single number you can track over time, compare against your stated payment terms, and use to catch collection problems before they become a cash flow problem.

Formula
DSO = (Accounts Receivable ÷ Revenue) × Number of Days

Calculate it

Days Sales Outstanding18 days

Worked examples

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Worked Example 1 — Wholesale Distributor

A wholesale distributor closes a quarter with $84,000 in accounts receivable and $420,000 in revenue over that 90-day quarter. DSO = ($84,000 ÷ $420,000) × 90 = 18 days. Against typical net-30 payment terms, an 18-day DSO means customers are paying well ahead of the deadline on average.

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Worked Example 2 — Consulting Firm

A consulting firm looks at a full year: $36,000 in accounts receivable against $360,000 in annual revenue. DSO = ($36,000 ÷ $360,000) × 365 = 36.5 days. If that firm also invoices on net-30 terms, a 36.5-day DSO means clients are paying roughly a week late on average — a signal worth investigating before it compounds.

Comparing your own DSO to your stated payment terms this way is the fastest way to tell whether a number on its own is fine or a warning sign — the same 18 or 36.5 days can be healthy or troubling depending on what you asked customers to agree to. Finmap recalculates DSO automatically every time a new invoice is issued or a payment lands, so you can watch the trend move in real time instead of rebuilding the calculation by hand at the end of each month or quarter.

Track this metric automatically

Finmap calculates it from your connected accounts and shows the trend over time — no spreadsheets to rebuild each month.

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More calculators

DSO Calculator: Days Sales Outstanding Formula & Example