Last updated October 13, 2026 · Report an error
Days Sales Outstanding (DSO) measures the average number of days it takes a business to collect payment after making a credit sale. A rising DSO can be an early warning sign of cash flow trouble even when sales look healthy.
This calculator divides accounts receivable by total credit sales, then multiplies by the number of days in the period to produce DSO.
How it works
Enter accounts receivable, total credit sales for the same period, and the number of days in that period (365 by default for a full year). The tool calculates the average number of days to collect payment.
- Enter accounts receivable.
- Enter total credit sales (same period).
- Enter days in period.
- Click Calculate to see your results.
Examples
A typical DSO for annual figures
$50,000 in accounts receivable against $600,000 in annual credit sales gives a DSO of about 30.4 days.
Who should use it
- Monitoring how quickly a business collects payment from credit customers.
- Comparing collections performance against stated payment terms.
Industry applications
- Accounting and financial analysis
- B2B businesses offering credit terms
Advantages
- Simple calculation from figures most businesses already track.
- Early warning indicator for collections problems before they become a cash crisis.
Limitations
- A single blended DSO can hide differences between fast- and slow-paying customer segments.
Common mistakes to avoid
- Including cash sales in the total sales figure, which understates true DSO for credit customers.
- Mismatching the period length between the days figure and the sales figure used in the calculation.
Best practices
- Track DSO over multiple periods and compare it against your standard payment terms to catch a slowing collections trend early.
Tips
- If DSO is creeping up relative to your stated payment terms, review your largest overdue accounts first — a handful of slow payers can skew the whole average.