DSO Calculator
Calculate Days Sales Outstanding to see how accounts receivable compares with credit sales.
How is dso calculator worked out?
Days Sales Outstanding is accounts receivable divided by credit sales for the period, multiplied by the number of days in that period. It expresses your outstanding receivables as the number of days of sales they represent.
DSO Calculator
Days Sales Outstanding
48.7 days
- Days beyond your terms
- 18.7 days
- Customers are paying later than agreed.
- Average daily credit sales
- $2,465.75
Show the working
| Accounts receivable | $120,000.00 |
| Credit sales in period | $900,000.00 |
| Days in period | 365 days |
| DSO | 48.7 days |
A gap this large between DSO and your stated terms usually points at a process problem — invoices going out late, missing purchase order numbers, or no systematic follow-up — rather than at customers deciding not to pay.
DSO is the headline measure of how quickly a business converts invoices into cash. On its own a single figure means little — what matters is the trend over time, and how it compares with the payment terms you actually offer.
The formula
DSO = (accounts receivable ÷ credit sales) × days in periodUse credit sales rather than total sales: cash sales never create a receivable, so including them understates DSO. Compare the result against your standard terms — a DSO of 45 on Net 30 terms means customers are taking roughly fifteen days longer than agreed.
What a DSO figure is actually telling you
DSO converts your receivables balance into a number of days of sales, which makes it comparable across periods of different size and across businesses of different scale. Read it against two things: your own trend, and your stated terms. A rising DSO means cash is arriving more slowly than it was, whatever the reason. A DSO well above your terms means the terms are not being observed — and since the gap is an average, it usually conceals a small number of very slow accounts rather than a uniform drift.
The limits of the measure
DSO is sensitive to the shape of your sales, not just your collections. A strong final month inflates receivables relative to the period's total sales and pushes DSO up even if every customer paid exactly on time; a quiet month does the reverse. Seasonal businesses see this most acutely, which is why DSO is best read as a trend across several periods, and why a countback method — working backwards through recent months' sales until the receivables balance is used up — gives a more stable figure for lumpy revenue.
Bringing DSO down
Most improvement comes from process rather than pressure. Invoice on the day the work completes rather than at month end; put the purchase order number on the invoice so it does not stall in accounts payable; send it to the person who pays rather than the person who briefed the job; ask when the customer's payment run happens and land before it; and follow up the day after the due date, every time. Shortening your stated terms rarely helps on its own if none of the above is in place.
Frequently asked questions
How do you calculate DSO?
Divide accounts receivable by credit sales for the period, then multiply by the number of days in that period. With 120,000 of receivables against 900,000 of annual credit sales, DSO is (120,000 ÷ 900,000) × 365, or about 49 days.
What is a good DSO?
It depends entirely on your terms and your industry, so the useful comparison is against your own payment terms and your own trend rather than a universal benchmark. A common rule of thumb is that DSO running more than about a third above your stated terms indicates a collections problem worth investigating.
Should DSO use total sales or credit sales?
Credit sales. Cash sales never create a receivable, so including them inflates the denominator and understates how long you are actually waiting to be paid.
Put the number on an invoice
The free invoice generator builds the document around your figures — line items, tax, payment terms — and downloads a print-ready PDF. No signup required.
Related calculators
- DSO Improvement / Cash Released CalculatorEstimate cash released when you shorten days sales outstanding.
- Accounts Receivable Turnover CalculatorCalculate how many times you collect average receivables in a period, and the implied days to collect.
- Average Collection Period CalculatorCalculate how many days it takes, on average, to collect payment from customers.
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