joehogue

Hello,
yes, they are using the ending inventory. The ratios are just looking at specific points in time. You can’t judge anything solely on the basis of the ratio. You must compare it with some benchmark which can be either the ratios of peer companies, the industry or the historical values of the company itself.
In case of payables turnover you calculate purchases as:
Purchases = Ending inventory  Beginning inventory + Cost of goods sold
which is I think clear. Purchases are simply indicated over time, it is impossible (or makes no sense) to calculate purchases at a point in time.
Is that what you wanted to know?