What days payable outstanding tells you
Accounts payable are the bills the business has received from suppliers but not yet paid. DPO expresses that balance as a number of days of cost of goods sold, so you can set it against the payment terms your suppliers give you.
A result of 30 days means the business took about 30 days, on average, to pay its suppliers. If suppliers allow 45 days, the business is paying ahead of its terms. If they allow 14 days, it is paying later than agreed.
Why the calculator divides by cost of goods sold
Payables arise from what the business buys, not from what it sells, so the calculator divides by cost of goods sold, as its cited source does. Dividing by revenue instead would mix selling prices with costs and make DPO look shorter. Some analysts divide by purchases, which is cost of goods sold adjusted for the change in inventory. The two give different results when inventory rises or falls during the period, so check which version a published figure uses before you compare.
The calculator uses a 365-day year by default. Some texts use 360 days, which gives a slightly lower result. Match the days to the period your cost figure covers.
Reading a high or low result
- A higher DPO keeps cash in the business for longer, which reduces the cash tied up in day-to-day operations. It can reflect favorable terms negotiated with suppliers. It can also be a sign of cash pressure: paying late can strain supplier relationships, lead to stricter terms or cost early-payment discounts.
- A lower DPO means suppliers are paid quickly. That may be a choice, for example to take early-payment discounts, or a condition set by suppliers, but it uses cash sooner.
Compare DPO with your suppliers’ terms and with earlier periods rather than with a general figure.
What DPO does not show
- Accounts payable can include bills for services and overheads that are not part of cost of goods sold, such as utilities or professional fees. These raise the payables balance without adding to the cost it is divided by, so DPO can overstate how long inventory suppliers wait.
- It is an average across all suppliers. One large overdue account can hide behind many paid on time.
- For a business with little cost of goods sold, such as many service businesses, the result can be very large and hard to interpret.
Average vs ending balances
Cost of goods sold builds up over the period, while payables are measured on a single date. Averaging the opening and closing balances gives a figure closer to what the business typically owed suppliers. To use the average, open “Add opening balances to use averages” and enter payables at the start of the period. If you leave it blank, the calculator uses ending payables. A large purchase just before the period end can push the ending balance, and DPO, well above the usual level.
Common mistakes
- Dividing by revenue instead of cost of goods sold.
- Including liabilities that are not owed to suppliers, such as accrued wages, taxes or loan repayments.
- Pairing a quarter’s cost of goods sold with 365 days.
- Comparing a DPO based on purchases with one based on cost of goods sold.
Related measures
Days sales outstanding measures the other side of trade credit: how long customers take to pay the business. The cash conversion cycle subtracts DPO from the days inventory is held plus the days taken to collect, so longer supplier credit shortens it. Inventory turnover uses the same cost of goods sold to show how quickly stock sells.