THE NUMORIX GUIDE
How to use the Days Sales Outstanding Calculator
Last reviewed September 14, 2026
What this calculator does
The engine calculates DSO = accounts receivable / annual revenue x 365.
Formula and method
The engine calculates DSO = accounts receivable / annual revenue x 365. It returns zero when annual revenue is zero and classifies the result as excellent at 30 days or less, good through 45, moderate through 60, and high above 60.
Variables and inputs
Enter Accounts Receivable and Annual Revenue as dollar amounts for a comparable reporting period. The route uses a 365-day year and does not request credit sales, average receivables, or a separate measurement period.
Worked example
For $150,000 of accounts receivable and $1,200,000 of annual revenue, DSO = 150,000 / 1,200,000 x 365 = 45.625 days, displayed as about 45.6 days. The engine therefore returns its moderate, collections-could-be-faster band.
How to interpret the result
DSO estimates the average number of sales days represented by receivables under the route's assumptions. A rising DSO can mean slower collection or looser credit terms and can tie up cash, while a lower DSO is not automatically good if it reflects overly restrictive customer terms.
Common mistakes to avoid
Use accounts receivable rather than total current assets, and use revenue from the same period. Credit sales are usually a better numerator base than total revenue when available. Do not confuse days with a percentage or read 45.6 as a contractual due date.
Assumptions and limitations
The engine uses ending receivables, total annual revenue, and a fixed 365-day year. It does not model average receivables, credit versus cash sales, aging, write-offs, seasonality, installment terms, or customer concentration. Industry and contract terms determine whether a value is reasonable.