Days sales outstanding (DSO) calculator
How many days pass, on average, between your invoice and the money in your account? Enter trade receivables and revenue: the result is instant and stays on your computer.
How DSO is calculated
The formula is: DSO = trade receivables ÷ revenue for the period × days in the period. Use revenue including VAT, since receivables include it too. With €120,000 outstanding and €600,000 invoiced over the last 12 months, DSO is 120,000 ÷ 600,000 × 365 = 73 days.
How to read it
Compare DSO with the payment terms you usually give (30, 60 or 90 days). The difference is how late your clients pay on average. Multiplied by one day of revenue, it tells you how much cash sits with your clients instead of in your account.
DSO is an average: one large client paying very late can outweigh many punctual ones. To act, you need to know which invoices are overdue and by how long, which is what a payment schedule shows.
How to bring it down
- Send a reminder a few days before the due date and a payment reminder the day after.
- Put the due date and IBAN on the invoice so the client has no excuse.
- Check weekly which clients pay later and later, and renegotiate terms with them.
- Watch your cash-flow forecast: delays show up before they become a problem.
Who pays you late, from your invoices
CassaChiara reads Italian XML e-invoices or the cassetto fiscale ZIP and shows who pays late, upcoming due dates and the next 90 days of cash.
Try it free with your invoices See pricingFrequently asked questions
What does DSO mean?
Days Sales Outstanding: the average number of days between issuing an invoice and getting paid.
Should revenue include VAT?
Yes, because trade receivables include VAT. Otherwise DSO comes out higher than it really is.
Which period should I use?
The last 12 months gives a stable figure. If your business is seasonal, use the last 3 months to see the current situation.
Is the data I enter sent anywhere?
No. The calculation runs in your browser and no figure leaves your computer.