What Is Days Sales Outstanding (DSO)?
What is days sales outstanding? It is the average number of days it takes a business to collect payment after a sale is made, and it is one of the core metrics for understanding cash flow health — a rising DSO means cash is taking longer to arrive even if revenue is growing.
Calculate DSO from your accounts receivable export and see which customers or invoice types are extending your collection cycle
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| Invoice ID |
| Customer |
| Invoice Date |
| Due Date |
| Payment Date |
| Amount |
| Status |
| Terms |
| Aging Bucket |
| Days Outstanding |
What usually goes wrong with it
DSO calculation requires matching invoices to payment records
An accounts receivable export shows open invoices; a payment export shows collected amounts. Calculating actual collection time requires matching Invoice ID across both files and computing the difference between Invoice Date and Payment Date.
DataMimi Datamimi joins the invoice export with the payment export by Invoice ID and calculates collection days as Payment Date minus Invoice Date for each matched row.
Open invoices inflate DSO if included without adjustment
Including unpaid invoices in the DSO calculation inflates the result because their 'collection time' grows every day they remain unpaid. A standard DSO calculation should exclude invoices that are open and not yet past due.
DataMimi It filters to paid invoices only before calculating the average, excluding open invoices that would inflate the result.
Different invoice payment terms make comparisons misleading
An invoice with Net 30 terms that was paid in 25 days is early; a Net 15 invoice paid in 25 days is late. A DSO average that doesn't account for payment terms produces a number that looks the same for both scenarios.
DataMimi Datamimi adjusts for payment terms by calculating days-early or days-late per invoice (Payment Date − Due Date), returning a terms-adjusted collection efficiency metric alongside the raw DSO.
Common questions
What is days sales outstanding as a formula?
DSO = (Accounts Receivable Balance ÷ Total Credit Sales) × Number of Days. For a 90-day period: DSO = (AR Balance at period end ÷ Credit Sales in the period) × 90. Alternatively, calculate per-invoice collection days and average them.
What is a good DSO for a B2B business?
DSO benchmarks vary by industry and payment terms. A DSO close to your standard payment terms (e.g., 35 days when terms are Net 30) is healthy. DSO consistently more than 15 days above terms signals a collection process problem.
How does days sales outstanding affect cash flow?
Every additional day of DSO delays cash inflows. A business with $1M/month in revenue and a DSO of 60 days has $2M tied up in receivables at any given time. Reducing DSO by 10 days frees $333K in cash that would otherwise be sitting in unpaid invoices.
What does Datamimi cost?
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DataMimi reads the file you actually have — merged cells, headers below row one, totals pasted at the bottom — and shows which rows and columns every number came from.
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