Days sales outstanding is the search behind a DSO calculator. It is how many days of credit sales are still sitting in accounts receivable.
The SBA glossary defines Days Receivable as accounts receivable divided by annual sales on credit, times 365. The days sales outstanding calculator uses the day count you type, and you leave it at 365 when you want that glossary line:
DSO = accounts receivable ÷ credit sales × days in the period
Receivables turnover = credit sales ÷ accounts receivable
Credit sales per day = credit sales ÷ days
Cash sales do not sit in receivables, so they stay out of the sales figure. A late fee on one overdue invoice is the invoice late fee calculator, and the late fee post walks that charge. DSO is the whole book.
These examples use the formula. They are not a collections forecast, and they are not business advice.
Fig 1
From the receivable balance to days
Credit sales only
Divide receivables by credit sales, then multiply by the days in the period. Turnover flips the first division.
What people mean by a good DSO
The glossary defines the ratio. It does not name a universal good number, and this calculator does not either. The useful comparison is the day count you got against the terms you actually offer.
If the terms are net 30 and the formula returns 30 days, the receivable balance matches one month of the credit sales you typed. Example 1 is that case. Example 8 is the same sales with a balance that matches net 15. A higher DSO means more of those credit sales are still unpaid. It does not, by itself, say which invoice is late. The page uses the single balance you type, not an aging report.
Example 1: 30 days on the calculator defaults
Inputs:
- accounts receivable: $30,000
- annual credit sales: $365,000
- days in the period: 365
DSO: 30,000 ÷ 365,000 × 365 = 30 days
Receivables turnover: 365,000 ÷ 30,000 = 12.1666, shown as 12.17×
Credit sales per day: 365,000 ÷ 365 = $1,000.00
Calculator result
Days sales outstanding
- Accounts receivable
- $30,000.00
- Annual credit sales
- $365,000.00
- Days in the period
- 365 days
30 days
days sales outstanding
- Receivables turnover
- 12.17×
- Credit sales per day
- $1,000.00
- Accounts receivable
- $30,000.00
Check it from the daily line. $30,000 ÷ $1,000.00 = 30 days. One month of credit sales is unpaid. If your terms are net 30, this book matches those terms on the average. One invoice inside the $30,000 can still be older. The average will not show it. Example 9 splits a balance so you can see that.
Example 2: a slower book
Inputs: receivables $80,000, credit sales $480,000, days 365.
DSO: 80,000 ÷ 480,000 × 365 = 60.8333, shown as 60.8 days
Turnover: 480,000 ÷ 80,000 = 6×
Credit sales per day: 480,000 ÷ 365 = $1,315.07
Calculator result
Days sales outstanding
- Accounts receivable
- $80,000.00
- Annual credit sales
- $480,000.00
60.8 days
days sales outstanding
- Receivables turnover
- 6×
- Credit sales per day
- $1,315.07
- Accounts receivable
- $80,000.00
Daily sales times the day count gets back to the balance: 1,315.07 × 60.8 is about $80,000. The page’s exact path is the one formula, then it rounds the day count. Against a net 30 term, 60.8 − 30 = 30.8 days past that term on the average.
Example 3: a short balance on large credit sales
Inputs: receivables $12,000, credit sales $600,000, days 365.
DSO: 12,000 ÷ 600,000 × 365 = 7.3 days
Turnover: 600,000 ÷ 12,000 = 50×
Credit sales per day: 600,000 ÷ 365 = $1,643.84
Most of this revenue has already been collected. What remains is 7.3 days of credit sales. If a large share of customers pay at the register, those receipts should not be inside the $600,000. Example 5 shows how that mix moves the day count.
Example 4: what if receivables rise by $20,000
Hold Example 1’s credit sales at $365,000 and the period at 365 days. Change receivables from $30,000 to $50,000.
DSO: 50,000 ÷ 365,000 × 365 = 50 days
Turnover: 365,000 ÷ 50,000 = 7.3×
Credit sales per day stays $1,000.00, because sales and the day count did not change.
The extra $20,000 is 20,000 ÷ 1,000 = 20 days. DSO moves from 30 to 50. Same credit sales, a larger unpaid balance, a longer average wait.
Example 5: the mistake of mixing in cash sales
The receivable balance is $30,000. Credit sales are $200,000. Cash sales are $165,000. The period is 365 days.
Credit only: 30,000 ÷ 200,000 × 365 = 54.75, shown as 54.8 days
Turnover on credit sales: 200,000 ÷ 30,000 = 6.666, shown as 6.67×
Credit sales per day: 200,000 ÷ 365 = $547.95
Calculator result
Days sales outstanding
- Annual credit sales
- $200,000.00
54.8 days
days sales outstanding
- Receivables turnover
- 6.67×
- Credit sales per day
- $547.95
- Accounts receivable
- $30,000.00
Now add the cash sales into the sales box: 200,000 + 165,000 = $365,000. That is Example 1’s sales figure, and it returns 30 days. The balance did not change. The day count fell by 54.8 − 30 = 24.8 days because cash receipts, which never sat in receivables, were treated as credit sales.
Of that $365,000, credit is 200,000 ÷ 365,000 = 54.8%. Cash is 165,000 ÷ 365,000 = 45.2%.
Fig 2 · 1/2
The $365,000 that got typed as credit sales
Only the $200,000 was sold on credit. Receivables stay $30,000.
Credit sales
$200,000
Cash sales
$165,000
Credit sales are $200,000, which is 54.8% of the mixed total.
Cash sales are $165,000. They do not belong in the DSO sales line.
Example 6: a 90-day quarter
Inputs: receivables $45,000, credit sales $180,000, days 90.
DSO: 45,000 ÷ 180,000 × 90 = 22.5 days
Turnover: 180,000 ÷ 45,000 = 4×
Credit sales per day: 180,000 ÷ 90 = $2,000.00
The balance is 45,000 ÷ 2,000 = 22.5 days of this quarter’s credit sales. That is not “a quarter of 90.” It is the formula. A year needs the year’s credit sales, the year-end or year-average balance you choose to type, and 365 days.
Example 7: a contractor’s year
Inputs: receivables $18,000, credit sales $96,000, days 365.
DSO: 18,000 ÷ 96,000 × 365 = 68.4375, shown as 68.4 days
Turnover: 96,000 ÷ 18,000 = 5.333, shown as 5.33×
Credit sales per day: 96,000 ÷ 365 = $263.01
Daily credit sales are small next to Example 1’s $1,000. The unpaid balance is still 68.4 days of them. If the bids are net 30, the average is 68.4 − 30 = 38.4 days past that term. The late-fee page can price one invoice. It will not rebuild this average.
Example 8: a balance that matches net 15
Inputs: receivables $15,000, credit sales $365,000, days 365.
DSO: 15,000 ÷ 365,000 × 365 = 15 days
Turnover: 365,000 ÷ 15,000 = 24.333, shown as 24.33×
Credit sales per day: $1,000.00, the same daily line as Example 1.
Half the receivable balance, same credit sales: 15,000 is half of 30,000, and 15 days is half of 30. If the terms are net 15, this average matches the terms. Example 1 matched net 30 on twice the balance.
Fig 3 · 1/5
Days sales outstanding
Each column is that example's DSO. The period is 365 days except where noted in the table.
Days
- DSO
| Category | DSO |
|---|---|
| Net 30 book | 30 |
| Net 15 book | 15 |
| Slower book | 60.8 |
| Credit only | 54.8 |
| Contractor | 68.4 |
The default book is 30 days. The net 15 balance is 15 days.
Credit sales alone, on the same $30,000, are 54.8 days.
Example 9: one old invoice inside the average
Credit sales are $730,000 for 365 days. Credit sales per day: 730,000 ÷ 365 = $2,000.00.
The receivable balance is $90,000. You already know $40,000 of it is one invoice, and the other $50,000 is the rest. The calculator still wants one balance. Run it three times so the average and the pieces use the same sales.
Whole balance: 90,000 ÷ 730,000 × 365 = 45 days. Turnover 730,000 ÷ 90,000 = 8.111, shown as 8.11×.
The rest: 50,000 ÷ 730,000 × 365 = 25 days. Turnover 14.6×.
The single invoice: 40,000 ÷ 730,000 × 365 = 20 days. Turnover 18.25×.
The pieces add: 25 + 20 = 45. The 45-day headline is 20 days of that one invoice plus 25 days of everything else. A 45-day DSO can hide a balance you would chase on its own. This split uses amounts you already separated. It is not an aging report the page builds for you.
Fig 4 · 1/3
Receivable balances on the same questions
Dollar balances. The day count depends on the sales beside them.
Accounts receivable
Default
$30,000
Slower book
$80,000
Whole book
$90,000
The default balance is $30,000 and lands at 30 days.
The $90,000 book lands at 45 days on $730,000 of credit sales.
How DSO sits next to turnover
Receivables turnover is the flip of the first division. In Example 1, sales ÷ receivables = 12.17×, and the day count ÷ that turnover is 365 ÷ 12.1666 = 30 days. You do not need both stories. The day count is the one to read against your terms. Turnover is the same fact as a count of collections in the period.
The accounts receivable turnover calculator is the related page when you want turnover from an average of two receivable balances. This DSO page uses the single balance you type.
DSO is also one leg of the cash conversion cycle. The cycle post adds inventory days and subtracts payable days. A 60.8-day DSO lengthens that cycle even when the stock turns quickly.
The nine results side by side
| Example | Receivables | Credit sales | Days | DSO | Turnover | Sales per day |
|---|---|---|---|---|---|---|
| 1. Defaults | $30,000 | $365,000 | 365 | 30 | 12.17× | $1,000.00 |
| 2. Slower book | $80,000 | $480,000 | 365 | 60.8 | 6× | $1,315.07 |
| 3. Short balance | $12,000 | $600,000 | 365 | 7.3 | 50× | $1,643.84 |
| 4. Receivables up $20,000 | $50,000 | $365,000 | 365 | 50 | 7.3× | $1,000.00 |
| 5. Credit sales only | $30,000 | $200,000 | 365 | 54.8 | 6.67× | $547.95 |
| 5. Cash mixed in | $30,000 | $365,000 typed | 365 | 30 | 12.17× | $1,000.00 |
| 6. Quarter | $45,000 | $180,000 | 90 | 22.5 | 4× | $2,000.00 |
| 7. Contractor | $18,000 | $96,000 | 365 | 68.4 | 5.33× | $263.01 |
| 8. Net 15 balance | $15,000 | $365,000 | 365 | 15 | 24.33× | $1,000.00 |
| 9. Whole book | $90,000 | $730,000 | 365 | 45 | 8.11× | $2,000.00 |
| 9. Rest of the book | $50,000 | $730,000 | 365 | 25 | 14.6× | $2,000.00 |
| 9. One invoice | $40,000 | $730,000 | 365 | 20 | 18.25× | $2,000.00 |
Row 5’s second line is the mistake. The $165,000 of cash sales pulled a true 54.8 days down to 30. Rows 9 add back together: 25 days + 20 days = 45 days.
Open the calculator on the credit-sales figure you can defend. Then read the day count next to the terms on the invoice, not next to a benchmark this page does not set.