DSO Calculator — Calculate Days Sales Outstanding

Closing (or average) AR balance for the period — trade receivables only.
Invoiced sales only. Cash and card sales settled at the point of sale never touch AR — leave them out.
Must be the exact window those credit sales were made in.
Used only to compare your DSO with your own terms. Leave blank or 0 to skip.
About this page

Scope note. DSO is a management metric, not a figure defined by an accounting standard — there is no single authoritative version of it, so state which method you used whenever you report it. This page implements the standard (simple) formula shown above. Some finance teams instead use a countback, or "exhaustion", method that unwinds the receivables balance month by month against each month's sales; it responds differently to a seasonal sales curve. Neither is more correct in the abstract. Nothing here is accounting, tax or financial advice — for statutory reporting, follow your accounting framework and your accountant.

How to calculate DSO: formula and worked example

Days Sales Outstanding: DSO = (Accounts Receivable ÷ Credit Sales) × Period Days

Average daily credit sales: daily = Credit Sales ÷ Period Days

Cash freed by collecting faster: cash released = (Credit Sales ÷ Period Days) × Days of DSO reduction

Gap against your own terms: gap = DSO − your Net term (in days), and cash in the gap = daily × gap

Worked example — these are the values already loaded in the form above, so pressing Calculate DSO reproduces every line:

A business closes a quarter with $90,000 of accounts receivable on $180,000 of credit sales over a 90-day period.

  • DSO = (90,000 ÷ 180,000) × 90 = 0.5 × 90 = 45.0 days
  • daily = 180,000 ÷ 90 = $2,000 per day
  • cash released by 5 days = 2,000 × 5 = $10,000
  • Invoicing on Net 30: gap = 45.0 − 30 = 15.0 days, and cash in the gap = 2,000 × 15 = $30,000

Read that last line literally: $30,000 of this business's own money is sitting in receivables beyond the term it agreed with its customers.

Getting the two inputs right

  • Credit sales, not total sales. Anything collected at the point of sale never enters AR. Putting it in the denominator drags DSO down without a single invoice being paid sooner.
  • Same window, both figures. A quarter-end AR balance belongs with that quarter's credit sales and Period Days = 90. Mixing a year-end balance with one month of sales produces a number that means nothing.
  • Same tax basis. AR balances usually include sales tax or VAT; revenue figures usually exclude it. Divide one by the other and DSO comes out overstated. Use both gross or both net.
  • Same currency. DSO is a count of days, so the currency cancels out of the division — but only if both inputs are in one currency. Convert first if you invoice in several.
  • AR net of what you will not collect. If a balance is written off or provided against as doubtful, leaving it in AR inflates DSO and hides the real collection speed.

How to read your DSO — against your own terms, not someone else's average

DSO is one number with one honest interpretation: over the period you chose, a dollar of credit sales sat in receivables for roughly this many days on average. Turning that into a verdict needs a reference point, and the only reference this page will give you is one you already own.

  • Compare it with the terms you actually invoice on. If your terms are Net 30 and your DSO is well above 30, receivables are on average aging past the term you agreed — the excess days are the slack between what your contract says and what your bank account sees.
  • DSO at or below your term is arithmetically possible when deposits, prepayments or early payers pull the average down. It means the typical invoice is settling inside the window you set.
  • Put a price on the gap. Multiply the excess days by average daily credit sales (daily × gap) and the abstraction becomes a cash figure — the calculator does this for you whenever you enter a Net term.
  • An average hides its own tail. A handful of very large, very late invoices can lift DSO while most customers pay on time. Before treating a high DSO as a company-wide problem, open the aged receivables list and look at which invoices are carrying it; the invoice aging calculator builds one from a pasted list.
  • The trend beats the level. Same formula, same period length, same definition, month after month. A DSO moving up tells you something even when you have no idea what the "right" level is.

We publish no "industry average DSO" here on purpose. Any single benchmark number blends businesses with different payment terms, customer mixes, credit policies and seasonality, so it cannot tell you whether your receivables are healthy. Your own terms and your own trend can.