SellersCalc

Working capital

DSO vs DPO vs DIO Calculator

Three day-counts that sound alike and pull in different directions. Here is what each measures and how they combine.

DSO = (accounts receivable ÷ revenue) × days; DIO = (inventory ÷ COGS) × days; DPO = (accounts payable ÷ COGS) × days. They differ in what they measure and which way you want them to move. DSO is how long customers take to pay you — lower is better. DIO is how long stock sits before selling — lower is better. DPO is how long you take to pay suppliers — higher is better, because supplier credit is free funding. That sign flip is the whole reason the three are easy to confuse. On $1.2M revenue, $720K COGS, $120K receivables, $110K inventory and $70K payables over 365 days: DSO 36.5, DIO 55.8, DPO 35.5. The first two add into an operating cycle of 92.3 days, and subtracting DPO gives a cash conversion cycle of 56.8 days — the stretch your own cash funds the business. Cutting receivables to $60K drops DSO to 18.3 and the cycle to 38.5; doubling payables to $140K lifts DPO to 71.0 and drops the cycle to 21.3, which is why negotiating supplier terms often beats chasing invoices. Already know your three day-counts? Feed them straight into the cash conversion cycle calculator instead. Enter your figures below to get all three from the books.

DSO vs DPO vs DIO Calculator — your numbers

Cash conversion cycle

56.78

DSO — days sales outstanding

36.50

DIO — days inventory outstanding

55.76

DPO — days payable outstanding

35.49

Operating cycle (DIO + DSO)

92.26

Estimate only. Results reflect exactly the numbers you enter — verify against your own accounting before making pricing decisions.

Embed this calculator on your site — free →

Worked examples

A $1.2M business on annual figures

Revenue for the period $1,200,000.00
Cost of goods sold $720,000.00
Average accounts receivable $120,000.00
Average inventory $110,000.00
Average accounts payable $70,000.00
Days in period 365
Cash conversion cycle 56.78
DSO — days sales outstanding 36.50
DIO — days inventory outstanding 55.76
DPO — days payable outstanding 35.49
Operating cycle (DIO + DSO) 92.26

DSO 36.5, DIO 55.8, DPO 35.5 — a 56.8-day cash conversion cycle.

Same business, supplier terms doubled

Revenue for the period $1,200,000.00
Cost of goods sold $720,000.00
Average accounts receivable $120,000.00
Average inventory $110,000.00
Average accounts payable $140,000.00
Days in period 365
Cash conversion cycle 21.29
DSO — days sales outstanding 36.50
DIO — days inventory outstanding 55.76
DPO — days payable outstanding 70.97
Operating cycle (DIO + DSO) 92.26

DPO rises to 71.0 and the cycle falls to 21.3 days — no sales change needed.

What DSO, DIO and DPO mean. All three are the same idea applied to a different part of the cash cycle: how many days money sits in one place. Two of them are clocks you want to run fast, and one is a clock you want to run slow.
TermStands forDays that…Formula
DSODays Sales Outstandingcustomers take to pay youreceivables ÷ revenue × days
DIODays Inventory Outstandingstock sits before sellinginventory ÷ COGS × days
DPODays Payables Outstandingyou take to pay supplierspayables ÷ COGS × days
How the three combine. Two identities connect them: the operating cycle is DIO + DSO, and the cash conversion cycle is DIO + DSO − DPO. DPO subtracts because supplier credit is time you are financed by someone else, so lengthening it shortens your own cash gap. On this calculator's default figures the three come out at DSO 36.5 days, DIO 55.8 days and DPO 35.5 days, giving a 92.3-day operating cycle and a 56.8-day cash conversion cycle — meaning cash leaves the business almost two months before it returns.
Reading them together rather than separately. A single one of these numbers cannot tell you whether the cycle is healthy, because they trade off against each other. Cutting DIO by holding less stock can raise DSO if it pushes you toward wholesale customers who pay on terms, and stretching DPO improves the cycle on paper while quietly costing supplier goodwill and early-payment discounts. Judge the combination, which is what the cash conversion cycle calculator reports as one figure.

The three ratios only mean something together. A DSO of 36 days reads well in isolation and badly next to a DPO of 15, because it means you are financing customers for three weeks longer than suppliers finance you. That difference is the cash conversion cycle, and it is the number that tells you whether growth will consume cash or release it — a business with a long cycle needs more working capital every time it grows.

Of the three levers, DPO is usually the cheapest to move and DIO the most valuable. Extending supplier terms costs a conversation; cutting DSO means tightening credit on customers who may leave; cutting DIO means selling faster or holding less, which the inventory turnover calculator and days of inventory calculator both measure directly. Once you know your cycle, size the cash it ties up with the working capital calculator.

Frequently asked questions

What is the difference between DSO, DPO and DIO?

They track three different delays. DSO measures how long customers take to pay you after a sale. DIO measures how long inventory sits before it sells. DPO measures how long you take to pay your own suppliers. DSO and DIO are money waiting to reach you; DPO is money you are legitimately holding on to.

Which one should be high and which should be low?

You want DSO and DIO low, and DPO high. Getting paid faster and selling stock faster both release cash; paying suppliers later keeps cash in your account longer at no interest. This is the one place in working capital where a bigger number is the good outcome, which is exactly why the three get mixed up.

Why do DIO and DPO divide by COGS instead of revenue?

Because both concern goods at cost, not at retail. Inventory sits on the balance sheet at what you paid, and supplier invoices are for what you owe, so dividing either by revenue would mix cost figures with marked-up ones and understate both. Only DSO uses revenue, because receivables are recorded at the price you charged.

What is a good cash conversion cycle?

It depends entirely on the model. Retailers with fast turns and supplier credit often run near zero or negative — Amazon is the classic negative-cycle example, funded by customers paying before suppliers are. A wholesale or made-to-order business commonly runs 60 to 90 days. Track your own trend rather than an industry number.

Should I use period-average or closing balances?

Averages, where you have them: (opening + closing) ÷ 2 for receivables, inventory and payables. A single closing balance picks up whatever the last week looked like, which distorts seasonal businesses badly. Use closing figures only when averages are not available, and stay consistent between periods.

Related calculators

Part of the Store Finance collection.